System, method, and apparatus for controlling power output distribution in  a hybrid power train

ABSTRACT

A system includes a hybrid power train including an engine, a first electrical torque provider, and a second electrical torque provider. The system further includes a load mechanically coupled to the hybrid power train. The hybrid power train further includes a clutch coupled to the engine and the second electrical torque provider on a first side, and coupled to the first electrical torque provider and the load on a second side. The system further includes an electrical energy storage device electrically coupled to the electrical torque providers. The system further includes a controller that performs operations to smooth torque commands for the engine and the second electrical torque provider in response to determining that a clutch engage-disengage event occurring or imminent.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/350,728 entitled SYSTEM, METHOD, AND APPARATUS FORCONTROLLING POWER OUTPUT DISTRIBUTION IN A HYBRID POWER TRAIN, filed onJan. 13, 2012 which claims the benefit of U.S. Provisional patentapplication 61/432,324 entitled SYSTEM, METHOD, AND APPARATUS FORCONTROLLING POWER OUTPUT DISTRIBUTION IN A HYBRID POWER TRAIN, filedJan. 13, 2011, each of which is incorporated herein by reference.

BACKGROUND

The technical field generally relates to hybrid power train systems, andmore particularly but not exclusively relates to control of hybrid powertrain systems operating in a motor vehicle. The introduction of two ormore power sources into a power train introduces the possibility ofselecting the power source for the load according to which power sourceis presently at a more optimal operating condition. For example, duringa transient load situation, an electric motor may respond more optimallythan an internal combustion engine, and the opportunity for the electricmotor to manage the transient portion of the load is introduced.However, selecting the device that is more optimal under the presentconditions, without considering future operating conditions, introducesthe possibility of reaching a system limit—for example running a batteryout of charge.

Additionally, certain operations may reduce the service life ofcomponents in the system, such as behaviors to save fuel economy thatresult in rapid cycling of battery charge. Further, the increased numberof devices in the system includes an increased number of constraints forthose devices that must be considered when coordinating devices to meetthe desired output. Certain devices may not be available for full outputin certain operating conditions, for example as an electric motor isheated the maximum power output becomes limited.

The optimal operating decisions for the devices also depend upon theduty cycle and operating conditions corresponding to a particularapplication. In addition, when a component in the system is failed orhas a fault, the optimal operating decisions may be significantlydifferent than when all components are operating correctly, but thedetermination of the new optimum remains complex. Further, a change in acomponent due to normal usage over time may alter the behaviors that areoptimal. For example, if an aged aftertreatment catalyst requires morefrequent regeneration events, or the maximum state-of-charge of an agedbattery is lower than in a new battery, the optimal behaviors of thehybrid power train may change over time.

Therefore, further technological developments are desirable in thisarea.

SUMMARY

One embodiment is a unique system, apparatus, and method for controllinga hybrid power train. Other embodiments include unique methods, systems,and apparatus to calibrate and utilize a hybrid power train controller.Further embodiments, forms, objects, features, advantages, aspects, andbenefits shall become apparent from the following description anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a hybrid power train architectureselectable between a series configuration and a parallel configuration.

FIG. 2 is a schematic illustration of mechanical and electricalconnections within an example hybrid power train, including vehicledynamics.

FIG. 3 illustrates an example relationship between a vehicle speed and astate-of-charge (SOC) target, including a high and low SOC targetboundary.

FIG. 4 is an illustration of an SOC target as a function of a storagedevice state-of-health (SOH).

FIG. 5 provides an illustration of example energy storage deviceconstraints and parameters, as a function of the SOC and SOH of theenergy storage device.

FIG. 6 is a depiction of considerations to determine electrical limitsin a hybrid power train.

FIGS. 7 and 8 depict an exemplary calculation for a propulsionelectrical power limit.

FIGS. 9 and 10 depict an exemplary calculation for a regenerationelectrical power limit.

FIG. 11 depicts an illustrative time line for engine start and stopoperations in a hybrid power train.

FIG. 12 is a schematic flow diagram of an operation to start an engineof a hybrid power train.

FIG. 13 is a schematic flow diagram of an operation to determine whethera predictive startup of an engine is indicated.

FIG. 14 is a schematic flow diagram of an operation to determine whethera rate of change of a SOC indicates a startup of an engine.

FIG. 15 is a description of an operation to determine whether a changein power demand indicates an engine start.

FIG. 16 is a schematic flow diagram of an operation to determine whethera second electrical torque provider predictive limit indicates a startupof an engine.

FIG. 17 is a description of a rule-based controller operation.

FIG. 18 is a schematic diagram of a rule-based controller operation.

FIG. 19 is a schematic diagram of a rule-based controller to operate aclutch.

FIGS. 20-26 depict an example basic cost optimization function for asystem including a hybrid power train.

FIG. 27 is an illustration of a number of efficiency functions providedas a function of operating conditions including machine shaft speedand/or output power.

FIGS. 28 through 32 depict an illustrative embodiment for capturing theresults of an analysis using an exemplary basic cost optimizationfunction into a controller usable data set, and operating a run-timecontroller in response to the controller usable data set.

FIG. 33 depicts an example operation to determine a λ value to provide avariable system response to a SOC offset.

FIG. 34 depicts another example operation to determine a λ value toprovide a variable system response to a SOC offset.

FIG. 35 depicts another example operation to determine a λ value toprovide a variable system response to a SOC offset.

FIG. 36 depicts another example operation to determine a λ value toprovide a variable system response to a SOC offset.

FIG. 37 through 43 depict an example operation to generate a controllercalibration matrix.

FIG. 44 illustrates an example controller rule-based run-time logic.

FIG. 45 is a schematic flow diagram of an operation to select a rulesbased controller or an optimizing controller.

FIG. 46 is a schematic flow diagram of an operation to operate anoptimizing controller.

FIG. 47 is an illustration of operations for an optimizing controller.

FIG. 48 is a schematic illustration of example clutch operations.

FIG. 49 is another schematic illustration of example clutch operations.

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended, any alterations and further modificationsin the illustrated embodiments, and any further applications of theprinciples of the invention as illustrated therein as would normallyoccur to one skilled in the art to which the invention relates arecontemplated herein.

Certain descriptions herein include a controller structured to performvarious operations. In certain embodiments, the controller forms aportion of a processing subsystem including one or more computingdevices having memory, processing, and communication hardware. Thecontroller may be a single device or a distributed device, and thefunctions of the controller may be performed by hardware or software.

In certain embodiments, a controller includes one or more modulesstructured to functionally execute the operations of the controller. Thedescription herein including modules emphasizes the structuralindependence of the aspects of the controller, and illustrates onegrouping of operations and responsibilities of the controller. Othergroupings that execute similar overall operations are understood withinthe scope of the present application. Modules may be implemented inhardware and/or software on computer readable medium, and modules may bedistributed across various hardware or software components.

Certain operations described herein include an interpreting operation.Interpreting, as utilized herein, includes receiving values by anymethod known in the art, including at least receiving values from adatalink or network communication, receiving an electronic signal (e.g.a voltage, frequency, current, or PWM signal) indicative of the value,receiving a software parameter indicative of the value, reading thevalue from a memory location on a computer readable medium, receivingthe value as a run-time parameter by any means known in the art, and/orby receiving a value by which the interpreted parameter can becalculated, and/or by referencing a default value that is interpreted tobe the parameter value.

Certain descriptions herein include methods, techniques, and/orprocedures including operational descriptions. Operations described areunderstood to be exemplary only, and operations may be combined ordivided, and added or removed, as well as re-ordered in whole or part,unless stated explicitly to the contrary herein. Certain operationsdescribed may be implemented by a computer executing a computer programproduct on a computer readable medium, where the computer programproduct comprises instructions causing the computer to execute one ormore of the operations, or to issue commands to other devices to executeone or more of the operations.

FIG. 1 is a schematic diagram of a hybrid power train architecture 100selectable between a series configuration and a parallel configuration.The architecture 100 includes clutch 108 positioned between a firstshaft mechanically coupled to a first electrical torque provider 104(or, electrical torque device, or ETD), and a second shaft mechanicallycoupled to an engine and to a second electrical torque provider 106.Each of the electrical torque providers 104, 106 is electronicallycoupled to one or more electrical storage devices (e.g. a battery,hypercapacitor, etc.). In certain embodiments, power electronics 118,120 are positioned between each electrical torque device and theelectrical storage, for example to convert voltages, rectify electricalpower, etc.

The first shaft 110 is mechanically coupled to a load 114. Any load 114known in the art is contemplated herein, including at least a vehicledrive wheel, a motor/generator, a generator/motor, an engine (e.g. ahydraulic engine), a WER motor, etc. The load 114 may include atransmission, additional gearing or differentials, a driveline, machineshafts, etc. In a first position, the open clutch 108 provides thesystem as a series drive system. The first electrical torque provider104 can draw power from the electrical storage device 116 and power theload 114, while the engine 102 can recharge the electrical storagedevice 116 through the second electrical torque device 106 as required.In a second position, the closed clutch 108 provides the system as aparallel drive system. The engine 102 and second electrical torquedevice 106 are mechanically coupled to the load. Either of theelectrical torque devices 106, 104 can de-couple from the shafts, forexample through an internal clutch or by de-magnetizing internalwindings, allowing the engine 102 to power the load 114, and/or theelectrical torque devices 106, 104 can add or subtract torque from theshafts 110, 112 to provide motive power or to regenerate the electricalstorage device 116. The architecture 100 is an example, and any systemthat operates in series, parallel, selectably series-parallel, and/orother hybrid configurations having two different load driving torqueproviders are contemplated herein.

Referencing FIG. 2, a schematic illustration of an system 200 ofmechanical and electrical connections within an example hybrid powertrain. The system 200 includes an engine 102 coupled to a starter 202and to a second electrical torque provider 106. The system 200 includesmechanical accessories 204 coupled to the engine 102 and to the secondelectrical torque provider 106. Mechanical accessories 204 may beselectively driveable by the engine 102 and/or second electrical torqueprovider 106, and/or may alternatively be selectively drivenelectrically. The system 200 further includes a hybrid clutch 108 thatcouples the engine 102 and the second electrical torque provider 106 toa transmission 210.

The system further includes a first electrical torque provider 104,which in the example is coupled to the transmission 210. In certainembodiments, the system 200 includes electrical accessories 208, whichmay be distinct devices from or at least partially shared devices withthe mechanical accessories 204. The electrical accessories 208 arecoupled via power electronics to a battery 116 (or other electricalenergy storage device(s)). In certain embodiments, the system 200includes a final drive 212 coupled to the transmission 210, such as arear axle gear and/or a differential, a wheel 214 coupled to the finaldrive 212, and/or vehicle dynamics 216 that affect the transfer of power(and/or torque) between the transmission 210 and the final motion of thevehicle or load.

FIG. 3 illustrates an example relationship 300 between a vehicle speedand a state-of-charge (SOC) target 306. The example includes a high SOCtarget boundary 302 and a low SOC target boundary 304. The examplerelationship 300 is non-limiting. In certain embodiments, the shape ofthe SOC target 306 may depend upon the characteristics of the battery,the weight of the vehicle, and/or the internal friction values of thevehicle. Information such as the SOC target 306 may be readilydetermined, such as by operating a vehicle of a selected weight betweenselected starting and stopping speed ranges, and determining an amountof charge restored to the battery 116 during deceleration operationsfrom each of the varying speed ranges.

FIG. 4 is an illustration 400 of an SOC target 412 as a function of astorage device state-of-health (SOH) 402. The illustration 400 shows afirst relationship 406 that enforces an increasing SOC target with astrong battery (e.g. high SOH). The relationship 406 is an example, andcan be determined according to selected criteria for the specificapplication, including a relationship where a degrading SOH may indicatethat a higher SOC target is appropriate. In certain embodiments, arelationship 408 of the SOC target with vehicle speed 404 is combinedwith the relationship 406 to determine the final SOC target 412. Theexample illustration 400 demonstrates each relationship 406, 408providing a factor for the final SOC target 412, and a multiplieroperation 410 between the factors 406, 408 to provide the final SOCtarget 412.

Other exemplary factors that may affect the final SOC target 412, incertain embodiments, include temperature (of the battery, ambient,etc.), deviation from SOC, and/or cost impact to respond tocharge/discharge under present conditions. The relationships 406, 408illustrated are exemplary. The multiplier operation 410 is exemplary,and other combining operations may be utilized.

FIG. 5 provides an illustration 500 of example energy storage deviceconstraints and parameters, as a function of the SOC and SOH of theenergy storage device. Example parameters to provide constrains on SOClimits include a maximum discharge power limit 502 (for exampleimplemented as a present SOC limit that enforces the discharge rate fromthe battery), a maximum charge power limit 504. The maximum dischargepower limit 502 is used to determine an energy storage discharge limit524, and the maximum charge power limit 504 is used to determine anenergy storage charge limit 526. In certain embodiments, a current SOC510 is utilized in a function 518 to determine a present energy storageconversion efficiency 528. In certain embodiments, a maximum SOC limit506 is utilized in conjunction with a current SOH 512, for example todetermine an energy storage SOC upper limit 530. In certain embodiments,a minimum SOC limit 508 is utilized with a current SOH 512 to determinean energy storage SOC lower limit 532. The relationships in theillustration are exemplary and non-limiting, and are readily determinedby one of skill in the art contemplating a particular system. Therelationships in the illustration 500 are usable, in one example, todetermine feasibility of particular calibration values or of variousplanned control behaviors.

FIG. 6 is a depiction of considerations 600 to determine electricallimits in a hybrid power train. Based on the amount of power availableon the electric bus via the operations of ETD2 (e.g. a second electricaltorque provider), storage, and the Accessories, the efficiencies of thebattery providing power, of the electrical torque devices providingpower, the efficiencies of the engine powering the electrical side (e.gincluding internal engine friction, etc.), the motoring or regenerationconstraints for first electrical torque device are computed. The maximummotoring or regeneration of the first electrical torque device can beutilized to determine the feasibility of particular calibration valuesor of various planned control behaviors. In the example, η_(pe1) andη_(pe2) are the power conversion efficiencies of the power electronics(not shown) positioned between the storage device and the respectiveelectrical torque devices, and η_(esp) is the conversion efficiency(e.g. chemical-electrical for a battery) of the electrical storage pack(or the electrical energy storage device) such as the battery.

FIGS. 7 and 8 depict an exemplary calculation 700 for a propulsionelectrical power limit. The calculations 700 illustrated are examplesand non-limiting. The calculations 700 utilize the available conversionefficiency information to determine the available power for propulsionfrom the first and second electrical torque providers. FIGS. 9 and 10depict exemplary calculations 800 for a regeneration power limit. Thecalculations 800 illustrated are examples and non-limiting. Thecalculations 800 utilize the available conversion efficiency informationto determine the available power for regenerating from the first andsecond electrical torque providers.

FIG. 11 depicts an illustrative time line for engine start and stopoperations in a hybrid power train. The first curve 1102 depicts exampleengine on request values. The second curve 1104 depicts an engine startpower command to the second electrical torque provider. The third curve1106 depicts the engine speed, and the fourth curve 1108 depicts thestate of the engine with regard to being considered in a running stateand/or fueling.

In the example 1100, a startup delay is implemented after the engine iscommanded ON and before the second electrical torque provider activelypowers the engine. When the engine speed reaches a specified value, theengine begins self-operation and the power from the second electricaltorque provider to the engine ramps off. After the engine is commandedto the off state, a stop delay is implemented before the engine is shutdown.

FIG. 12 is a schematic flow diagram of an procedure 1200 to start anengine of a hybrid power train. The procedure 1200 includes an operation1202 to determine whether a SOC of the battery indicates an engine startis desired. In response to the operation 1202 being YES, the procedure1200 includes an operation 1206 to command the engine start. In responseto the operation 1202 being NO, the procedure 1200 includes an operation1204 to determine whether the current power demand indicates that anengine start is desired. In response to the operation 1204 being YES,the procedure 1200 includes an operation 1206 to command the enginestart. In response to the operation 1204 being NO, the procedure 1200further includes an operation 1208 to determine whether a predictivestartup indicates an engine start. In response to the operation 1208being YES, the procedure 1200 includes an operation 1206 to command theengine start.

FIG. 13 is a schematic flow diagram of an operation 1208 to determinewhether a predictive startup of an engine is indicated. The exampleoperation includes an operation 1302 to determine whether a timederivative (or other time based rate of change) of the SOC of theelectrical storage device indicates that an engine start is indicated.In response to the operation 1302 being YES, the operation 1208determines at operation 1306 that a predictive startup indication isYES. In response to the operation 1302 being NO, the operation 1208includes an operation 1304 to determine whether a time rate of change ofthe hybrid power train power output indicates an engine start. Inresponse to the operation 1304 being YES, the operation 1208 determinesat the operation 1306 that a predictive startup indication is YES. Inresponse to the operation 1304 being NO, the operation 1208 includes anoperation 1308 to determine whether an electrical torque providerpredictive limit indicates an engine start. The operation 1308 includes,for example, determining that a capability of the electrical torqueprovider to start the engine is reducing with time, and that the systemmay soon encounter an operating condition where the electrical torqueprovider will not have the capability to start the engine. In responseto the operation 1308 being YES, the operation 1208 determines that apredictive startup indication is YES, in response to the operation 1308being NO, the operation 1208 determines at operation 1310 that apredictive startup indication is NO.

FIG. 14 is a schematic flow diagram of an operation 1202 to determinewhether a rate of change of a SOC indicates a startup of an engine. Theoperation 1202 includes an operation 1402 to determine a time rate ofchange of the SOC, and an operation 1404 to determine a total usablestorage capacity of the electrical storage device. The operation 1202further includes an operation 1406 to determine a ratio of the time rateof change to the total usable storage capacity. In a first example, theoperation 1202 includes an operation 1408 to determine if the ratio from1406 exceeds a threshold value, and YES provides the operation 1412 toindicate an engine start. A NO provides the operation 1410 to indicatethat an engine start is not indicated in response to the time rate ofchange of the SOC. In a second example, the operation 1202 includes anoperation 1414 to multiply the ratio from 1406 by a predetermined value,and an operation 1416 determine whether a current SOC exceeds the sum ofthe product from 1414 and a minimum allowable SOC. A determination ofYES from operation 1416 indicates an engine start.

In certain embodiments of the operation 1202, the δSOC/δt is filteredand/or rate limited, the thresholds of 1408, 1416 are adjusted accordingto a current SOH of the electrical storage device, a hysteresis isapplied to the thresholds of the operation 1408, 1416 (e.g. to preventstart request toggling of the engine), and/or the multiplying inoperation 1414 can be replaced with other mathematical operations, suchas raising the ratio to a predetermined power.

FIG. 15 is a description of an operation 1500 to determine whether achange in power demand indicates an engine start. In certainembodiments, the operation 1500 may be utilized in the procedure 1204.

The example operation 1500 includes a first option 1502, where the rateof change of the power demand is normalized, for example to a 0-1 value,by the described operation or any other method. The option 1502 includesraising the converted rate of change op power to a predetermined value,multiplying the result by a maximum power capability of the firstelectrical torque device, and subtracting the result from the maximumpower capability of the first electrical torque device. If the currentpower demand is greater than the result, an engine start is indicated.

The operation 1500 includes an additional or alternative option 1504,which includes determining a normalized value from 0-1 from the rate ofchange of the power demand, determining a power threshold from thenormalized value and a maximum power capability of the first electricaltorque device, and indicating an engine start of the current powerdemand exceeds the power threshold. In certain embodiments, the rate ofchange of the power demand may be filtered or rate limited, and/or ahysteresis value may be applied to the power demand thresholds whichindicate engine starting and stopping.

FIG. 16 is a schematic flow diagram of an operation 1600 to determinewhether a second electrical torque provider predictive limit indicates astartup of an engine. In certain embodiments, the operations 1600 may beutilized in a procedure 1200.

The operation 1600 includes an operation 1602 to determine a currentsecond electrical torque provider propulsion power limit (e.g. availablepower that is not required to operate accessories, etc.), and operation1604 to determine whether the current second electrical torque providerpropulsion power limit has fallen below a threshold. If the operation1604 is YES, then the operation 1608 sets the predictive limit enginestart to YES, and if the operation 1604 is NO, then the operation 1606sets the predictive limit engine start to NO.

In certain additional or alternative embodiments, a hysteresis value isapplied to the threshold, e.g. to prevent request toggling. In certainembodiments, the rate of change of the second electrical torque providerpropulsion limit with time, the rate of change of the propulsion limitto the relative magnitude of the current propulsion limit and/or to therelative magnitude of the maximum propulsion limit may be utilized toset the engine predictive start value. Other values that may be utilizedto set the engine predictive start value include the rate of change ofthe second electrical torque provider propulsion limit with timerelative to the machine power demand, a threshold power limit determinedfrom the machine power demand and an incremental power required forengine start, and/or a threshold power limit from a calibration based onengine size and/or other starting effort indicator.

FIG. 17 is a description of a rule-based controller operation 1700. Incertain embodiments, the rule-based controller operation 1700 isutilized when machine power demand is greater than zero. In thedescribed operations, the ETD1 is a first electrical torque provider,and the ETD2 is a second electrical torque provider. The engaged clutchlogic may be substituted with parallel operation of the hybrid powertrain, and the disengaged clutch logic may be substituted with seriesoperation of the hybrid power train.

FIG. 18 provides an illustrative charging curve 1802 describing chargingpower applied to a battery based upon the current SOC relative to a SOCtarget value. In the example, the charging effort increases as thebatter gets further from the target SOC. The example curve 1802, or anyother charging effort curve, may be utilized with any feature,algorithm, or embodiments described herein. An example operating spacediagram 1804 illustrates a speed-load map for the hybrid power trainwith an engine performance curve mapped onto the diagram 1804. Above athreshold operating space, approximately equating to high poweroperations as illustrated, an example hybrid power train is scheduled tooperation in a parallel configuration with the electrical portionassisting the engine. Below a threshold operating space, approximatelyequating to lower power operations as illustrated, an example hybridpower train is scheduled to turn the engine off and operatingelectrically.

FIG. 19 is a schematic diagram of a rule-based controller including anoperation space diagram 1804. The diagram 1804 is similar to the diagram1804 from FIG. 18, although the operating dividers 1910, 1912, 1914 neednot be in the same positions. At a first region 1902, the example hybridpower train operates the engine and the electric motor(s) in a powerassist configuration. At a second region 1904, the example hybrid powertrain operates the engine and the electric motor(s) in a parallelconfiguration. At a third region 1906, the example hybrid power trainoperations in a series manner, providing all motive power from a firstelectrical torque provider and charging the battery from the engine asrequired or when it is determined to be efficient. In a fourth operatingregion 1908, the example hybrid power train operates on electric poweronly, providing charging to the battery from the engine only asrequired.

The example regions 1902, 1904, 1906, 1908 are non-limiting. In certainembodiments, other example operations include engaging the clutch and/orswitching into a parallel configuration in response to: the engine beingrunning, and/or the machine power demand being greater than a parallelpower threshold. In certain embodiments, other example operationsincludes disengaging the clutch and/or switching into a seriesconfiguration in response to: the machine power demand being positivebut below the parallel power threshold, the machine power demand beingnegative and machine shaft speed is below an engine stall thresholdvalue. In certain embodiments, operations include applying a hysteresisin either or both directions (switching to parallel and/or switching toseries), and/or applying hysteresis to regions 1902, 1904, 1906, 1908.

FIGS. 20-26 provide a description of a basic cost optimization functionfor a system including a hybrid power train. The examples of FIGS. 20-26are illustrative and non-limiting. FIG. 20 illustrates a system 2000 andan example propulsion efficiency calculation. The efficiencies of powerflows 2004, 2006 from the battery 116 to the motive power (e.g.including power electronics conversion efficiencies) are illustrated.The efficiency 2002 of each electronic torque provider includes thechemical conversion efficiency of the battery, the power electronicsefficiencies, and the electrical to mechanical energy conversionefficiency of each of the motors.

FIG. 21 illustrates a system 2100 and an example generating efficiencycalculation. The efficiencies of the power flows 2104, 2106, 2108, 2110are illustrated. In one example, the generating efficiency 2102 of eachelectrical torque provider is shown, accounting for the batterychemistry, the power electronics, and the mechanical to electricalconversion efficiency of each torque provider. The second electricaltorque provider 120 is illustrated with a corrected efficiency η_(EG11)to account for the friction effects of turning the engine 102 when thesecond electrical torque provider 120 is regenerating. However, the baseefficiency η_(EG1) may alternatively be used, where the engine 102 canbe mechanically decoupled from the second electrical torque provider 120and/or where the friction of the engine 102 is explicitly modeled.

FIGS. 22 through 26 provide an example basic optimization cost functionthat is utilizable to compare relative costs of specific operationbehaviors. Any other cost algorithm is contemplated herein. The examplecalculations 2200, 2300, 2400, 2500, 2600 consider battery chargingconditions, battery discharging conditions, and the entire cycleefficiency for storing and retrieving electrical energy from thebattery. The following nomenclature is utilized:

-   -   P_(EMi)=i^(th) motor net power out to mechanical shaft (+ve)    -   P_(EG) _(i) =i^(th) generator net power in from mechanical shaft        (−ve)    -   η_(EM) _(i) =i^(th) motor net electrical efficiency from power        source in to shaft power out    -   η_(EG) _(i) =i^(th) generator net electrical efficiency from        shaft power source in to electric power in Note: for EG₁ the        efficiency is impacted in energy recovery mode (regen braking)        as the engine acts as a friction load (η_(EG11))    -   Q_(LHV)=The lower heating value (also known as net calorific        value, net CV, or LHV) of a fuel is defined as the amount of        heat released by combusting a specified quantity (initially at        25° C. or another reference temperature)

FIG. 27 is an illustration 2700 of a number of efficiency functions2702, 2704, 2706, 2708, 2710, 2712, 2714 corresponding to an internalcombustion engine 2702, 2708, electrical torque providers in a motoringmode 2704, 2706, and the electrical torque providers in a generatingmode 2710, 2712, and the combined efficiency of the second electricaltorque provider in a generating mode mechanically coupled to the engine2714. The efficiency functions are provided as a function of operatingconditions including machine shaft speed for the electrical torqueproviders and the engine brake specific fuel consumption, and as afunction of engine power for engine fuel consumption. Utilization of thesystem of equations of FIGS. 22-26 require efficiency values at variousoperating conditions, such as the efficiency values provided in FIG. 27.Calibrated efficiency tables can be readily determined for a given realor planned system.

FIGS. 28-32 depict an illustrative embodiment 2800 for capturing theresults of an analysis using an exemplary basic cost optimizationfunction into a controller usable data set, and operating a run-timecontroller in response to the controller usable data set. The controllerusable data set includes a behavior matrix 2802, and provides a powerdivision description 2812, where an internal combustion engine and anumber of electrical torque providers are operated in response to thepower division description. The controller usable data set furtherincludes an control interface for responding to an electrical energystorage device SOC target, and an SOC correction factor 2808 determinedfrom the SOC target and a current SOC. In one example, the behaviormatrix 2802 provides values for power output from the various devices inresponse to the machine power demand and/or the vehicle speed. Aspecific value 2804 from the behavior matrix 2802 provides the currentoperating point. The initial power division description is provided tothe online computation 2812, that corrects for the current battery SOCcorrection factor (λ), for the differences in shaft speeds 2810, and forthe current clutch state 2806 (or hybrid power train configuration).

Referencing FIG. 29, the illustration 2900 includes the clutch closed(or a parallel configuration) and enforces the boundary condition thatall shafts are spinning at the same speed. The best efficiency from amotoring efficiency map 3100 is utilized, for example provided byindividual motoring efficiency maps 3102, 3104. If the clutch is notclosed (or a series configuration), referencing FIG. 32 the illustration3200 allows for an optimization of the total electrical effort,enforcing the condition that the electrical torque device an the loadside of the clutch must provide the machine power demand, and that theengine and the electrical torque device on the engine side of the clutchmust provide net zero power. The λ value in FIG. 32, which allows forvariable system response with regard to the SOC variation, may itself bea function of the series-parallel state of the system, and/or the clutchposition.

Referencing FIG. 33, a λ correction value 3300 determined in response toa SOC correlation 3302 is illustrated. The λ calculation 3304, in anexample embodiment, increases non-linearly away from the target SOC (atthe target SOC, the SOC deviation=zero). The positive and negative SOCdeviation sides may have asymmetric λ responses. The SOC target in FIG.33 is determined in response to the vehicle speed. Referencing FIG. 34,the illustration 3400 provides a SOC determination in response to one ormore parameters in the SOC calculation 3302. Referencing FIG. 35, in theillustration 3500 a base λ is utilized and modified by a SOH correlation3502 of the battery, yielding the λ output of the correlation 3504. Thebase λ value may, in one example, be determined according to theembodiments of FIG. 33 and/or FIG. 34. An example correlation 3504includes the λ value increasing more rapidly at lower SOC deviationvalues in response to the SOH of the battery degrading. Referencing FIG.36, the illustration 3600 includes the SOH correction factor correlation3602 being a function of depth of discharge, cycle life, cost ratios offuel and electricity, battery chemistry (e.g. more robust battery typesand/or expense of the battery type may affect the desired response toSOC deviation).

Referencing FIG. 28, the behavior matrix 2802 may be stored on acontroller during run-time. The parameter P_(DMD) is the machine powerdemand, Spd_(veh) is the vehicle speed, machine shaft speed, or otherparameter that can be correlated to efficiency data e.g. as depicted inFIG. 27. The value λ is the battery SOC correction factor that definesthe strength of the system response to the SOC deviation. The clutchstate can be used alternatively with series- or parallel-configurationin certain embodiments. Referencing FIG. 31, the input to 3102, 3104 isthe total electrical torque contribution and machine shaft speed, andthe output of 3106 is the torque contribution for one or both of theelectrical torque devices. The output of 3106 can be for either devicewhere two devices are present; where one device is defined by the load,the second device may be defined by the output of 3106.

FIGS. 37 through 43 depict an example operation to generate a controllercalibration matrix. The operations in FIGS. 37 to 43 are examples andnon-limiting, and may be performed offline or during down time on thecontroller, although a sufficiently powerful controller mayalternatively run the operations of FIGS. 37 to 43 during run-time. Theexample operations determine an optimal or progressively improving setof behavior matrices that may be utilized as behavior matrices 2802during run-time on a controller. In one example, a behavior matrix 2802determined to improve the operating cost of a hybrid power train isprovided to a controller as a calibration matrix.

FIG. 37 is an illustration 3700 providing example operations to define amission profile (e.g. a driving route), and to determine the machineshaft speed over the mission. The mission and shaft speeds may bedata-based, planning logic, or determined in any other manner.Continuing in FIG. 38, the illustration 3800 continues with behaviormatrices that are developed, either randomly, with educated guesses,utilizing previous calibration matrices, etc. Continuing with FIG. 39,the illustration includes dividing the potential power output states ofthe power devices into discrete operation conditions, and operating thebehavior matrices through the mission, sequentially changing thebehavior matrices in a genetic algorithm format, Monte Carlo format, orthrough any other sequencing means known in the art. Each potentialsolution is checked for feasibility (e.g. battery power runs too lowwith certain behaviors, etc.), and the most fit members of the feasiblesolutions are passed to the next generation. Continuing with FIG. 42,the illustration 3800 includes replicating and allowing gene crossingbetween members, and continuing with FIG. 43 a desired mutation rate isapplied. The solutions are checked for convergence—according to anydesired criteria such as a reducing improvement rate. In certainembodiments, a most fit member after convergence is determined may beprovided as a calibration matrix.

FIG. 44 illustrates an example controller rule-based run-time logic4400. A machine power demand 4402 is determined. If the hybrid powertrain is operating in a series power mode, a transition is made toseries operation 4404. If the hybrid power train is operating in aparallel power mode, a transition is made to a parallel power mode 4406.In the series power mode 4404, if a change in the machine power demandexceeds the power available on the electrical torque provider that ispowering the load, the logic 4400 transitions to a parallel operatingmode request 4412. From the parallel operating mode request 4412, if theparallel operating mode is not allowed, the logic 4400 transitions to amaximal power output mode 4420 for the electrical torque provider thatis powering the load. It is noted at the maximal power output mode 4420that the machine power demand is unachievable.

If the parallel operating mode is allowed at parallel operating moderequest 4412, the logic 4400 transitions to parallel operation 4418.During parallel operation 4418, an example operation includes maximizinga power output of an electrical torque provider on the engine-side ofthe clutch, and making up any additional required power from the engineto achieve the machine power demand.

At the series operation 4404, if there is a negative change in themachine power demand present that is greater than the negative poweravailable from the electrical torque provider that is powering the load,the logic 4400 concludes with operating mode 4410 requesting paralleloperation for a negative power assist, and/or providing the electricaltorque provider that is powering the load with the lowest availablepower.

At the series operation 4404, if the change in the machine power demandis within the capability of the electrical torque provider that ispowering the load, an optimizing algorithm 4408 is executed, for exampleas described herein in accordance with a predetermined behavior matrix.In another example, a run-time optimization as illustrated in FIGS.46-47 or similar operation may be performed.

At the parallel operation 4406, if a positive power demand change isrequested that is greater than that available on the electrical torqueprovider on the load-side of the clutch, an operation 4416 includesmaximizing the electrical torque provider on the load-side of theclutch, increasing or maximizing the electrical torque provider on theengine-side of the clutch, and providing the balance of the machinepower demand with the engine.

At the parallel operation 4406, if a negative power demand change isrequested that is greater than that available on the electrical torqueprovider on the load-side of the clutch, an operation 4414 includesminimizing the electrical torque provider on the load-side of theclutch, decreasing or minimizing the electrical torque provider on theengine-side of the clutch, and providing the balance of the machinepower demand with the engine (e.g. down to an engine braking maximumvalue, if available).

At the parallel operation 4406, if a machine power demand change isrequested that is less than that available on the electrical torqueprovider on the load-side of the clutch, the optimizing algorithm 4408is executed, for example as described herein in accordance with apredetermined behavior matrix. In another example, a run-timeoptimization as illustrated in FIGS. 46-47 or similar operation may beperformed.

The described operations in FIG. 44 provide an optimization routine whenmachine power demand changes are small and within the capability of oneof the electrical torque devices to meet. The operations provide forrapid response to machine power demand changes with the opportunity tooptimize operations during steadier operating periods. The operationsdescribed are illustrative and non-limiting.

Referencing FIG. 45, a schematic flow diagram of a procedure 4500 tooperate an optimizing controller is illustrated. The procedure includesan operation 4502 to determine the SOC target, and an operation 4504 todetermine whether a change in the machine power demand is greater thanthe electrical torque provider on the load side of the clutch. Inresponse to the operation 4504 being YES, the procedure 4500 includes anoperation 4508 to operate a rules-based controller (e.g. see FIG. 44,operations 4414, 4416, 4412). In response to the operation 4504 beingNO, the procedure 4500 includes an operation 4506 to operate anoptimizing controller—either offline calibrated (e.g. a behavior matrix)or a procedure such as in FIGS. 46 and 47.

FIG. 46 is a schematic flow diagram of a procedure 4600 to operate anoptimizing controller. The operations of the procedure 4600 includeaccessing a previous cycle cost and determining a current cycle cost(operation 4602), determining whether the cost is increasing (operation4604 being NO) or decreasing (operation 4604 being YES). Where operation4604 indicates NO, the error is degrading and the increment direction(of the power division between devices, e.g.) is reversed (operation4608), the power division is incremented (4610), the electrical torqueprovider on the load side of the clutch is adjusted to meet transientpower demands (operation 4612), and the updated power commands inresponse to the power division incrementing and the transientadjustments to the electrical torque provider on the load side of theclutch are outputted (operation 4614). Where the cost is decreasing(operation 4604 being YES), the procedure includes an operation 4616 tocontinue incrementing the power division description in the samedirection, and the concluding operations 4610, 4612, 4614. The procedure4600 thereby “walks” the power division description into favorable costconditions, is operable in run-time, and provides quick response tochanges in the machine power demand.

In certain embodiments of FIGS. 46 and 47, operations includes applyinga noise function to the increment value and/or the cost comparisonvalue, and/or operating a closed loop controller with either the sign ofthe cost change, or a rate of the cost change as an error value. Theclosed loop controller may be P, PI, fuzzy logic, or other controllertype. An example closed loop controller includes gain scheduling orother features to increase response (rate of change in the powerdivision description) as desired, for example where the rate of changeof the cost is high. In certain embodiments, increments may be appliedto engine-total electric contribution split; then additional incrementlogic to split within the electric system, or increments applied only toengine-total electric split, with rules or efficiency lookup values(e.g. as in FIG. 31) to determine how to split the total electriccontribution among ETDs (electrical torque devices).

FIG. 47 is an illustration of operations 4700 for an optimizingcontroller to determine a current cost 4718 of operations. Theoperations 4700 are usable, in one example, with a procedure 4600 suchas illustrated in FIG. 46. The operations 4700 are self-explanatory, butsome clarification is provided herein. The switch 4702 provides anoutput of the reciprocal of the total efficiency (power electronicsefficiency multiplied by storage device and drive efficiencies) of thesecond electrical torque provider when the power of the secondelectrical torque provider is positive, and otherwise provides the totalefficiency of the second electrical torque provider. The product block4706 provides an equivalent fuel cost of the second electrical torqueprovider. The switch 4704 provides a gain value for the secondelectrical torque provider depending upon the motoring or generatingstate. The product block 4708 provides a total efficiency of the firstelectrical torque provider, the switch 4710 provides the totalefficiency or the reciprocal thereof based on the motoring state of thefirst electrical torque provider, the switch 4712 provides a gain valuefor the first electrical torque provider depending upon the motoring orgenerating state, and the product block 4714 provides an equivalent fuelcost for the first electrical torque provider. The sum block 4716outputs the equivalent fuel cost for the current operating condition ofthe hybrid power train.

The operations 4700 are illustrative and non-limiting. Other operationsto determine a fuel cost or other cost equivalent for a hybrid powertrain are contemplated herein. In certain embodiments, the operation4700 normalize to a unitless cost value, a currency cost (e.g. $), orother selected baseline for comparison. In certain embodiments, costsfor emission, audible noise, aftertreatment operations, regeneration ofaftertreatment components, service life impacts to batteries oraftertreatment components, or any other cost values are determined. TheSOC correction cost is determined by any method, including total chargecycle efficiency for generating and storing battery power, fuel versusregeneration estimate of future charging source (e.g. an electricalcharger present at the destination), and/or a cost determined utilizingthe principles in FIGS. 33-36 (e.g. SOC correction cost as f(λ)). TheSOC correction cost may further include an integral term to increase thecost as a deviation persists over time. In certain embodiments, fuel LHVmay include a nominal engine thermal efficiency, and/or the currentengine thermal efficiency.

Referencing FIG. 48, example clutch operations 4800 are illustrated. Ina first operation 4802, the clutch is open and the vehicle is beingpropelled in an all electric mode (from ETD1). In a second operation4804, the clutch is open and the vehicle is being propelled in an allelectric mode, where an engine start has been requested. In a thirdoperation 4806, the clutch is closed and the vehicle is being propelledin a parallel operating mode from both the engine and electricaldevices—the battery is discharging in the operations 4806. In a fourthoperation 4808, the clutch is closed and the vehicle is being propelledin a parallel operating mode, with battery charging occurring.Referencing FIG. 49, further example clutch operations 4900 areillustrated. In an operation 4902 the clutch is open and the vehicle isbeing propelled in a series operating mode, with the engine charging thebattery through the second electrical torque device. In anotheroperation 4904, the clutch is open and the vehicle is not beingpropelled—the first electrical torque device is returning vehiclekinetic energy to the battery. In another operation 4906, the vehicle isstopped, the clutch is open, and the engine is recharging the batterythrough the second electrical torque provider.

An exemplary technique for controlling a hybrid power train isdescribed. The technique includes an operation to determine a machineshaft torque demand and a machine shaft speed, and in response to themachine shaft torque demand and the machine shaft speed, the techniqueincludes an operation to determine a machine power demand. The operationto determine a machine shaft torque demand includes any torquedetermination understood in the art, including without limitationinterpreting an accelerator pedal position or request, interpreting acruise control or power take-off control position or request value,interpreting a datalink or network-provided torque request. Theoperation to determine the machine shaft speed includes any shaft speeddetermination understood in the art, including receiving a sensor inputrepresentative of the machine shaft speed, receiving a machine shaftspeed value from a datalink or network, and/or receiving one or morevalues of other parameters from which the machine shaft speed may becalculated.

The machine power demand is a description of the usable power at themachine shaft that achieves the machine torque demand at the presentmachine shaft speed. The machine shaft includes any power receivingdevice positioned downstream of all power providing components within ahybrid power train included in the machine. For example, and withoutlimitation, the machine shaft may be a driveline, a transmissiontailshaft output, a rear axle of a vehicle, a power take-off shaft, apump input shaft.

The machine includes a hybrid power train. The hybrid power train, asused herein, includes a power providing device having at least two powerproviders operating with differing power mechanisms. An exemplary hybridpower train includes an internal combustion engine and at least oneelectrical torque provider. Another exemplary hybrid power trainincludes an internal combustion engine and a hydraulic torque provider.In certain embodiments, the description herein stating an electricaltorque provider can be adapted for a hydraulic torque provider, and thedescription herein stating an electrical energy storage device can beadapted for a hydraulic accumulator. Further, the description hereinstating power electronics positioned between an electrical torqueprovider and an electrical energy storage device can be adapted for apower converter within a hydraulic power system.

The exemplary technique further includes an operation to adjust themachine power demand to a non-zero value in response to determining thatthe machine shaft speed is zero and the machine shaft torque demand isgreater than zero. One of skill in the art will appreciate that themachine power required to achieve a given torque target is zero when theshaft speed is zero; however, when the torque request is greater thanzero the final power output of the machine is expected to be a valuegreater than zero. The adjusted power value is any zero speed powervalue understood in the art. Exemplary adjusted power values include avehicle launch power determined according to the desired launch powerfor a selected operator feel, and/or a zero speed power value determinedto avoid harm to any driveline or power train component and to providethe desired initial acceleration—for example a limit within thetransmission, driveline, or rear axle gear may define the zero speedpower limit. In certain embodiments, the zero speed power value isdetermined in response to a vehicle mass, or other load inertiadescription, where a vehicle mass or load inertia description isavailable.

The exemplary technique further includes an operation to determine apower division description between an internal combustion engine and oneor more electrical torque providers. The power division description is apower amount provided by each component, such that the sum of the powerfrom each component combines to the machine power demand. The powerdivision description may be an absolute or relative value. The techniquefurther includes operating the internal combustion engine and theelectrical torque provider(s) in response to the power divisiondescription. Operating the internal combustion engine and the electricaltorque provider(s) in response to the power division descriptionincludes, without limitation, providing the power from the devicesaccording to the power division description, and/or progressingacceptably from a current power output for each device to the power fromthe devices according to the power division description.

For example, the power division description may include 50% of themachine power demand to be provided by the internal combustion engine,25% from the first electrical torque provider, and 25% from the secondelectrical torque provider, and the technique operates the devicesaccordingly. In certain embodiments, the devices are mechanicallycoupled to operate at an identical speed, or at a fixed ratio of speedsbetween the devices, and the technique includes providing the determinedpower amounts for each device at the fixed speed. In a further example,where all of the devices are operating at 1,000 rpm, the techniqueincludes operating the internal combustion engine at a torque value toprovide the determined power contribution for the internal combustionengine at 1,000 rpm, and operating each of the electrical torqueproviders at a selected torque to provide the determined power amountfor each of the electrical torque providers at 1,000 rpm. In certainembodiments, the power devices are coupled through a power splitter, atorque converter, or other device that allows the speeds of each deviceto float or change in relative ratios between each other.

An exemplary technique further includes an operation to determine anengine cost function that includes an engine operating cost as afunction of engine power output. The engine cost function may accountfor the specific cost of achieving the engine power output at themachine shaft speed, or the engine cost function may further account forthe specific cost of achieving the engine power output at a selectedspeed within a range of allowable speeds where the speed of the engineis allowed to change. The specific cost includes a fuel cost, an enginewear cost, an oil service life cost, and/or any other cost understood inthe art. In certain embodiments, the specific cost is determined fromfuel consumption estimated to achieve the engine power output. Forexample, a speed-load table mapping a brake specific fuel consumption(BSFC) may be implemented to determine the specific cost for theinternal combustion engine. Additionally or alternatively, anincremental cost in the considered system (e.g. equivalent miles ordollars toward an engine re-build, equivalent miles or dollars toward anengine oil change, etc.) is provided for consideration into a costfunction.

The exemplary technique further includes an operation to determine anelectrical cost function that includes the electrical torque provideroperating cost as a function of the electrical torque provider poweroutput. In certain embodiments, the electrical cost function determinesan equivalent fuel cost of providing power with the electrical torqueprovider. An exemplary equivalent fuel cost includes the efficiency ofcorresponding power electronics, where the power electronics areelectrically positioned between the corresponding electrical torqueprovider and an electrical energy storage device.

The electrical cost function may further include the efficiency ofconverting power from the electrical energy storage device to provide tothe electrical torque provider. In certain embodiments, the entire cycleefficiency of utilizing a present unit of charge on the electricalenergy storage device, converting the unit of charge through the powerelectronics, dissipating the unit of charge in the electrical torqueprovider to provide mechanical power, consuming a subsequent unit offuel in the internal combustion engine to power a generator, convertingthe mechanical power in the generator to a unit of charge that isprovided through the power electronics to the electrical energy storagedevice to replace the present unit of charge that is under considerationfor present consumption. In addition to the entire cycle efficiency, andadditional or alternate embodiment considers the estimated fraction ofall future charge events that will be provided by regenerative braking,and the efficiencies of the regenerative braking. For example, anembodiment where 5% of all electrical power to the electrical energystorage device is provided by regenerative braking may indicate a highercost from the electrical cost function relative to an embodiment where10% of all electrical power to the electrical energy storage device isprovided by regenerative braking.

In certain embodiments, the electrical cost function includes agenerating operating region, and the electrical cost function includesan electrical energy storage efficiency and/or an electrical energystorage efficiency and recovery efficiency (i.e. the entire storage andrecovery cycle efficiency). For example, the cost of the internalcombustion engine providing a power output that is greater than themachine power demand, with the electrical torque provider simultaneouslyoperating in a generating operating region is described by the costfunctions and considered when determining the power divisiondescription. In certain embodiments, the technique further includes anoperation to determine the power division description in response to theengine cost function and the electrical cost function.

The electrical cost function may be a function averaging the entireelectrical system, and/or a function provided for each electrical torqueprovider, with each electrical torque provider considered independently.In certain embodiments, a second electrical torque provider isconsidered independently by determining a second electrical costfunction that includes a second electrical torque provider operatingcost as a function of a second electrical torque provider power output.The technique further includes determining the power divisiondescription further in response to the engine cost function, theelectrical cost function, and the second electrical cost function. Anexemplary second electrical cost function further includes an efficiencyof the power electronics corresponding to the second electrical torqueprovider. In certain embodiments, the second electrical cost functionincludes a generating operating region, and accounts for a secondstorage efficiency and/or a second storage and recovery cycleefficiency.

In certain embodiments, the technique includes operating the hybridpower train in one or more operating modes. In a first operating mode,the technique includes disengaging a clutch between the internalcombustion engine and the first electrical torque provider, andproviding all of the machine power demand with the first electricaltorque provider. In a second operating mode, the technique includesengaging the clutch between the internal combustion engine and the firstelectrical torque provider and providing all of the machine power demandwith the internal combustion engine. In a third operating mode, thetechnique includes engaging the clutch between the internal combustionengine and the first electrical torque provider and dividing the machinepower demand between the internal combustion engine and the firstelectrical torque provider. In a fourth operating mode, the techniqueincludes engaging the clutch between the internal combustion engine andthe first electrical torque provider and dividing the power between theinternal combustion engine and the second electrical torque provider. Ina fifth operating mode, the technique includes engaging the clutchbetween the internal combustion engine and the first electrical torqueprovider and dividing the power between the first electrical torqueprovider and the second electrical torque provider. In a sixth operatingmode, the technique includes engaging the clutch between the internalcombustion engine and the first electrical torque provider and dividingthe power between the internal combustion engine, the first electricaltorque provider, and the second electrical torque provider. Thedescribed operating modes are exemplary and non-limiting. In certainembodiments, the clutch includes a range of positions between open andclosed. In certain embodiments the hybrid power train may functionwithout a clutch, including in a series or parallel arrangement, andfurther including by coupling power from the engine and one or moreadditional power providers through a power splitter, torque converter,or other coupling arrangement known in the art.

An exemplary technique further includes an operation to determine a costdisposition parameter, and determining each of the cost functions inresponse to the cost disposition parameter and a plurality ofcorresponding cost functions. For example, the cost dispositionparameter may include a number of drive cycle routes, each one having aneffect on the cost functions, where the technique includes selecting oneof the cost functions, or a set of the cost functions, in response tothe cost disposition parameter. Non-limiting examples of cost functioneffects according to the cost disposition parameter include an emissionscost effect (e.g. due to varied emissions targets or penalties), a fueleconomy cost effect, an oil service life cost effect, a systemresponsiveness cost effect, a noise emissions cost effect, and/or abattery service life effect. The implementation of a cost dispositionparameter allows one of skill in the art to prioritize differing aspectsof a total cost according to the environment of the system, or thepriorities of the operator.

For example, a first cost disposition parameter corresponds to a firstset of cost functions, a second cost disposition parameter correspondsto a second set of cost functions, and the technique includesdetermining whether the first cost disposition parameter or the secondcost disposition parameter is to be utilized in the present applicationof the technique. Further exemplary cost disposition parameters includea duty cycle category and/or a drive route parameter. Exemplaryoperations to determine each cost function in response to the costdisposition parameter include selecting the cost functions correspondingto the cost disposition parameter, and/or interpolating between twoproximate cost functions according to the cost disposition parameter.

Certain further embodiments of the technique include an operation toadjust the power division description in response to an electricalstorage device state-of-charge (SOC). An exemplary technique includesdetermining the electrical cost function(s) that describe the electricaltorque provider(s) operating cost as a function of the power output forthe corresponding electrical torque provider, and further as a functionof the SOC for the electrical energy storage device.

In certain embodiments, the technique includes determining a vehiclespeed, and determining the power division description in response to themachine power demand and the vehicle speed. In a further embodiment, thetechnique includes determining a number of nominal power divisiondescriptions as a two-dimensional function of the vehicle speed and themachine power demand. The technique further includes determining thepower division description by performing a lookup operation utilizingthe plurality of nominal power division descriptions. For example, thelookup operation includes cross-referencing the vehicle speed andmachine power demand to a table having nominal power divisiondescriptions, and selecting the nominal power division descriptionclosest to the vehicle speed and machine power demand. The exemplarylookup operation may further include interpolating and/or extrapolatingin one or both dimensions.

Certain exemplary embodiments include the power division descriptionproviding the power division between the internal combustion engine, afirst electrical torque provider, and a second electrical torqueprovider. An exemplary technique further includes disengaging a clutchpositioned between the internal combustion engine and the secondelectrical torque provider in response to determining that the secondelectrical torque provider provides the entire machine torque demand.

In certain embodiments, the engine cost function includes an emissionscost for the engine—for example determined from the nominal emissions ofthe engine at the speed and torque indicated by the present engine speedand the contemplated power contribution of the engine. A furtherexemplary embodiment includes the engine cost function having a secondemissions cost. For example, the first engine emissions cost may bedetermined for NO_(x) emissions and the second engine emissions cost maybe determined for particulate emissions. Non-limiting examples of engineemissions utilized for the engine cost include a cost of NO_(x) output,a cost of CO output, a cost of CO₂ output, a cost of particulate output,a cost of metal or ash output determined according to estimated oilutilization at the considered engine operating conditions, and/or a costto emissions of blowby estimated at the considered engine operatingconditions. The quantification of any emissions value may be determinedaccording to any economic terms available, including at least a cost ofemissions compliance, an economic value of an emissions efficientvehicle determined according to market considerations, a regulatory costof various vehicle emissions levels, and/or a cost to remove theconsidered emissions from the environment after release.

In certain further embodiments, the engine cost function furtherincludes a secondary effect cost. Exemplary and non-limiting secondaryeffect costs include an incremental life loss of an aftertreatmentcomponent, an incremental regeneration cost of the aftertreatmentcomponent, and/or an incremental operating cost of the aftertreatmentcomponent.

For example, and without limitation, an engine operating condition maycontribute an incremental amount to a life loss of an aftertreatmentcomponent—for example by contributing an incremental particulate amountto a particulate filter, the filter will require a regeneration event ata future time which will remove an incremental amount of the servicelife of the aftertreatment component and cost a quantifiable amount.Accordingly, a cost according to the incremental life loss of theaftertreatment component is attributable to the particulate emission bythe engine secondary to the direct emissions cost of the particulateemission.

In another example, and without limitation, the engine operatingconditions may contribute an incremental amount to a regeneration costof the aftertreatment component, and/or offset the regeneration cost ofthe aftertreatment component. In the example, an engine operatingcondition that provides a passive regeneration amount to theaftertreatment component (e.g. by providing sufficient temperature andoxygen for an incremental amount of soot to be oxidized) may be deemedto be a lower cost operation than an engine operating condition thatprovides a low temperature, and that will, over time, require active(and presumably fuel consuming) regeneration efforts. The associatedfuel cost, aftertreatment component life cost (e.g. due to highertemperatures in the aftertreatment component from active regenerationrelative to passive regeneration), or other costs associated with theengine operating condition relative to regenerating the aftertreatmentcomponent can be quantified and considered in the engine cost function.In certain further embodiments, one or more of the emissions cost orsecondary effect costs include a discontinuity in the cost function.

In another example, the engine operating condition contributes to theincremental operating cost of an aftertreatment component. For example,and without limitation, a selective catalytic reduction (SCR) systemprovides a reagent (typically urea or NH₃) in response to NO_(x)emissions from the internal combustion engine. Accordingly, the engineoperating condition, and associated NO_(x) output, contributes to theoperating cost of the SCR system, and the secondary cost associated withNO_(x) emissions can be quantified. In a further embodiment, in certainSCR systems, the ratio of NO to NO₂ in the engine affects the efficiencyof the SCR system, and the specific NO_(x) components of the engine canbe utilized in determining the secondary cost of the NO_(x) emissions.

The described power division operations may be performed when themachine power demand is positive or negative, and any power provider inthe system may be providing power of a positive or negative magnituderegardless of the magnitude of the machine power demand. Exemplary andnon-limiting examples include the machine power demand being positive,with the internal combustion engine providing positive power and anelectrical torque provider providing negative power (e.g. to regeneratea battery). Another exemplary and non-limiting example includes themachine power demand being positive, with the internal combustion engineproviding negative power (e.g. by motoring without fueling) and anelectrical torque provider providing positive power.

In certain embodiments, the power division description includes anengine braking target power value. The engine braking target power valueincludes a negative amount of power to be provided by the engine. Theengine provides negative power according to the components available ina particular system, including without limitation, negative powerprovided by compression braking, compression braking with variable valvetiming, backpressure from a variable geometry turbine or an exhaustthrottle, negative power from vacuum provided by an intake throttle,and/or any other negative power implementation understood in the art. Incertain embodiments, the negative power may be available only indiscrete increments (e.g. according to a number of cylinders used forcompression braking). In certain embodiments, the power divisiondescription is corrected according to the discrete negative powerincrements available from the engine, and/or the engine selects anearest negative power operating condition and an electrical torqueprovider corrects the machine power output to meet the machine powerdemand.

Another exemplary technique includes an operation to determine a machineshaft torque demand and a machine shaft speed, and in response to themachine shaft torque demand and the machine shaft speed, the techniqueincludes an operation to determine a machine power demand. The techniquefurther includes an operation to determine a power division descriptionbetween an internal combustion engine, a first electrical torqueprovider, and a second electrical torque provider. The technique furtherincludes an operation to determine a clutch position, where the clutchposition is engaged or disengaged. The descriptions herein utilize aclutch position, however unless stated explicitly to the contrary,certain embodiments determine whether a hybrid power train is in aparallel arrangement or a serial arrangement, where the clutch engagedcorresponds to the parallel arrangement and the clutch disengagedcorresponds to the serial arrangement.

The clutch, for embodiments having the clutch, is interposed between thefirst electrical torque provider on a first side and the internalcombustion engine and the second electrical torque provider on a secondside. In certain further embodiments, a load is on the side of theclutch having the first electrical torque provider. The load receivesthe power output of the hybrid power train, and is at any positiondownstream of all power providing components in the hybrid power train.Exemplary and non-limiting loads include the drive wheels of a vehicle,a transmission tail shaft, a vehicle drive line, a power takeoff shaft,or a generator output shaft.

The exemplary technique further includes an operation to determine abaseline power division description in response to a vehicle speed andthe machine power demand. The vehicle speed, in certain embodiments, maybe substituted with a load kinetic energy description, such as arotating kinetic energy of a flywheel, rotating machine, etc. Thetechnique further includes an operation to determine an SOC deviationfor an electrical energy storage device. The SOC deviation is thedifference between a present SOC of the electrical energy storage deviceand a target SOC for the electrical energy storage device.

The electrical energy storage device is electrically coupled to thefirst electrical torque provider and the second electrical torqueprovider. The description herein includes a single electrical energystorage device coupled to both electrical torque providers, howeverexcept where explicitly stated to the contrary an electrical energystorage device may be coupled to only a single electrical torqueprovider. Further, additional electrical energy storage devices may bepresent in a given system, each device coupled to at least oneelectrical torque provider. For example, and without limitation, ahyper-capacitor or ultra-capacitor may be incorporated into theelectrical system and provide additional electrical energy storagecapacity and electrical energy transient control.

The exemplary technique further includes an operation to adjust thebaseline power division description in response to the SOC deviation andthe clutch position. In certain embodiments, determining the SOCdeviation for the electrical energy storage device includes determininga difference between a present SOC and a target SOC. In certainembodiments, the technique includes an operation to adjust the SOCdeviation in response to a present vehicle speed, a temperature of theelectrical energy storage device, a state-of-health (SOH) of theelectrical energy storage device, the machine power demand, and/or anintegrated state-of-charge deviation over time. The operation to adjustthe SOC deviation includes either an adjustment of the target SOC,and/or an adjustment directly of the SOC deviation downstream ofdetermining a difference between the present SOC and the target SOC.

An exemplary operation to adjust the SOC deviation in response to thepresent vehicle speed includes reducing the SOC deviation in response toan increasing vehicle speed, and/or reducing the SOC target value inresponse to the increasing vehicle speed. In certain embodiments, thereduction in the SOC target value is made in response to determining anamount of the kinetic energy of the vehicle that will be recharged tothe battery in response to a future deceleration event. The efficiencyof a generator, the power electronics between the generator and theelectrical energy storage device, and the chemical efficiency of theelectrical energy storage may all be estimated or calculated todetermine the SOC target value. Additionally, the fraction of thevehicle kinetic energy likely to be recovered is estimated orcalculated.

In certain embodiments, the operational history of the vehicle may beconsidered, for example by tracking an SOC before and an SOC after avehicle deceleration event. A driver that utilizes service brakesheavily will yield a lower regeneration recovery percentage, and adriver that decelerates too slowly, allowing engine and vehicle frictionto provide the bulk of the deceleration force will likewise yield alower regeneration recovery percentage. Accordingly, the techniquefurther includes, in certain embodiments, tracking data to determine anSOC recovery value in response to the vehicle speed, and provides theSOC deviation adjustment in response to both the vehicle speed and theSOC recovery value.

An exemplary operation to adjust the SOC deviation in response to thetemperature of the electrical energy storage device includes increasinga SOC deviation, and/or increasing the SOC target value in response to alower temperature of the electrical energy storage device. In certainbatteries, a storage capacity of the battery is reduced in response to alower battery temperature. The specific amount of battery capacityreduction with temperature is known to one of skill in the art havinginformation normally provided by a battery manufacturer and/or by simpleempirical sampling. In certain embodiments, the target SOC is increasedto account for the increased battery capacity with temperature. Incertain embodiments, only a fraction of the increased battery capacityis utilized, especially, in one example, where a subsequent batterytemperature decrease is expected (resulting in a subsequent dischargeregardless of system need). Exemplary situations where subsequentdischarge is expected include a determination that an ambienttemperature has reduced significant and/or an extended period of a lowload operation of the hybrid power train.

An exemplary operation to adjust the SOC deviation in response to a SOHof the electrical energy storage device includes an operation toincrease the SOC deviation in response to a reduced SOH of theelectrical energy storage device (e.g. to increase a system response tothe SOC deviation), an operation to reduce the SOC target in response tothe reduced SOH (e.g. recognizing that a total capacity of theelectrical energy storage device is reduced, and/or that each chargecycle of the electrical energy storage device reduces the service life),and/or an operation to increase the SOC target in response to thereduced SOH (e.g. recognizing that each charge cycle of the electricalenergy storage device reduces the service life). The response to adjustthe SOC target in response to the reduced SOH, in certain embodiments,is further determined according to present operating conditions. Anexemplary operation includes increasing the target SOC in response to areduced SOH during highly transient conditions to prevent the electricalenergy storage device from becoming depleted, and cyclically increasingand/or decreasing the target SOC in response to the reduced SOH duringsteady state conditions to minimize the number of the electrical energystorage device charge cycles.

The operation to adjust the SOC deviation in response to the machinepower demand includes an operation to decrease the SOC deviation and/orthe SOC target value in response to a high machine power demand.Decreasing the SOC target value in response to a high machine powerdemand maximizes initial system response to the machine power demand. Incertain embodiments, in response to a sustained high machine powerdemand, the SOC target value is increased, for example after theinternal combustion engine has reached an operating point where themachine power demand can be met with the engine alone. The increase ofthe SOC target value allows the system to have extra energy capacity torespond to ongoing power demands.

The operation to adjust the SOC deviation in response an integrated SOCdeviation over time includes an operation to increase the SOC deviationas the SOC deviation is sustained. In certain embodiments, the gain onthe integrated SOC deviation is intentionally positioned to allow aprescribed amount of overshoot/undershoot in the SOC, to avoid cyclingthe SOC too rapidly and degrading the quality of the electrical energystorage device. In certain alternate or additional embodiments, the gainon the integrated SOC deviation is positioned to allow the SOC todeviate for a prescribed period of time, but to enforce the SOC targetafter extended periods away from the target. The prescribed period oftime may be related to the time of event occurrences where an SOCdeviation is considered beneficial—for example the time to climb a shorthill or to merge onto an interstate from a lower speed ramp. Thedescribed utilizations of the integrated SOC are exemplary andnon-limiting.

An exemplary baseline power division description includes a totalelectrical contribution and a total engine contribution. The exemplarytechnique further includes, in response to determining the clutch isengaged, an operation to adjust the baseline power division descriptionby dividing the total electrical contribution between a first electricaltorque provider and the second electrical torque provider in response tothe machine shaft speed. For example, a system includes a firstelectrical torque provider and a second electrical torque provider, andthe technique includes determining an efficiency and maximum power ofeach of the electrical torque providers at the present machine shaftspeed, and selecting a power for each of the electrical torque providersthat maximizes the total electrical contribution efficiency.

In certain embodiments, the technique further includes an operation todetermine a net power flux to the electrical energy storage device inresponse to the SOC deviation. The exemplary technique further includesadjusting the baseline power division description further in response tothe net power flux. In certain embodiments, the net power flux is addedto the total electrical contribution, and subtracted from the totalengine contribution, such that the machine power provided by the hybridpower train is not affected by the net power flux. The technique furtherincludes providing the adjusted total electrical contribution, anddetermining a contribution for each of the first electrical torqueprovider and the second electrical torque provider in response to theadjusted total electrical contribution, an efficiency for the firstelectrical torque provider, a capacity of the first electrical torqueprovider, an efficiency of the second electrical torque provider, and/ora capacity of the second electrical torque provider.

An exemplary technique further includes, in response to determining theclutch is disengaged, an operation to adjust the baseline power divisiondescription by commanding the second electrical torque provider toachieve the machine power demand, by commanding the first electricaltorque provider to provide the net power flux to the electrical energystorage device, and by commanding the internal combustion engine topower the first electrical torque provider. The system operating withthe clutch disengaged is operating in a series operating mode, whereonly the second electrical torque provider is mechanically coupled tothe load, and the second electrical torque provider accordingly appliesall of the machine power demand. The first electrical torque provider isdecoupled from the load, but coupled to the electrical energy storagedevice, and the internal combustion engine can power the firstelectrical torque provider to charge the electrical energy storagedevice.

Several exemplary and non-limiting baseline power division descriptionsare providing following. Any of the power division descriptions mayinclude absolute or relative values. Relative power values may beprovided in terms of the machine power demand (e.g. a percentage of themachine power demand), or relative to any other variable in the system.Any one or more of the power contributions individually may be negativeor positive, and the sign of the machine power demand may be negative orpositive.

A first example includes a total electrical contribution and a totalengine contribution, where the total electrical contribution and thetotal engine contribution combined provide the machine power demand. Asecond example includes a power contribution for each of the internalcombustion engine, the first electrical torque provider, and the secondelectrical torque provider, where the total power contributions providethe machine power demand. A third example includes a total electricalcontribution, a total engine contribution, and a net power flux to theelectrical power storage device, where the total electricalcontribution, the total engine contribution, and the net power fluxcombine to provide the machine power demand.

A fourth example includes a power contribution for each of the internalcombustion engine, the first electrical torque provider, the secondelectrical torque provider, and a net power flux to the electrical powerstorage device, where the total power contributions and the net powerflux provide the machine power demand. A fifth example includes a totalelectrical contribution, a total engine contribution, a net power fluxto the electrical power storage device, and a net power flux toaccessories, where the total electrical contribution, the total enginecontribution, the net power flux to the electrical energy storagedevice, and the net power flux to the accessories combine to provide themachine power demand. A sixth example includes a power contribution foreach of the internal combustion engine, the first electrical torqueprovider, the second electrical torque provider, a net power flux to theelectrical power storage device, and a net power flux to accessories,where the total power contributions, the net power flux to theelectrical energy storage device, and the net power flux to theaccessories provide the machine power demand.

The exemplary technique further includes reducing the SOC deviationand/or reducing a response to the SOC deviation in response to anincreasing vehicle speed. An exemplary embodiment includes increasing aresponse to the SOC deviation in response to a magnitude of the SOCdeviation, and/or increasing a response to the SOC deviation over timein response to the SOC deviation being maintained. A further embodimentincludes responding to the SOC deviation with a proportional and/orintegral response.

An exemplary technique includes an operation to determine the SOCdeviation in response to a target SOC. The technique further includesdetermining the target SOC in response to a vehicle speed—for examplereducing the target SOC in response to an increased vehicle speed andincreasing the target SOC in response to a decreased vehicle speed.Another exemplary technique includes determining the target SOC inresponse to a vehicle mass. Exemplary operations to determine the targetSOC in response to the vehicle mass include reducing the SOC as afunction of the total vehicle kinetic energy (determined, for example,as proportional to a baseline mass kinetic energy calibration, or as afull model), or increasing the SOC at low or zero total vehicle kineticenergy. In a further embodiment, the technique includes increasing thetarget SOC over a range of operating conditions in response to anincreased vehicle mass. A vehicle having a higher mass stores a greateramount of kinetic energy in motion, and requires deeper withdrawals fromthe electrical energy storage device during acceleration events such ashigh acceleration operation and/or climbing hills. Accordingly, relativeto a vehicle having a lower mass, the technique operated in a vehiclehaving a higher mass may increase the high target SOC and/or decreasethe low target SOC. All described behaviors are exemplary andnon-limiting.

In certain embodiments, the technique includes determining the targetSOC in response to an electrical energy storage device capacity. Theelectrical energy storage device capacity varies under certain operatingconditions, including temperature, age, and SOH. In certain embodiments,the technique includes determining a higher target SOC in response to anincreased temperature of the electrical energy storage device,determining a higher or lower target SOC in response to an agedelectrical energy storage device, and/or determining a higher or lowertarget SOC in response to an electrical energy storage device having alow (or degraded) SOH. All described behaviors are exemplary andnon-limiting.

With an aged electrical energy storage device, having a lower totalcapacity than a new electrical energy storage device, the technique mayrequire a higher target SOC due to the inability to store as much of theregenerative electrical energy available during challenging duty cycleevents such as rolling hills or stop-and-go traffic. Accordingly, thetechnique sets a higher target SOC during certain operations. Duringother engine operations, for example during high speed level operation,the technique sets a lower target SOC to provide for a greater marginfor accepting electrical energy from regeneration during subsequentvehicle deceleration. One of skill in the art, having the benefit of thedisclosures herein, can determine how to set the target SOC in responseto an aged electrical energy storage device and the generally knownconditions of a particular application in which the hybrid power trainis installed. All described behaviors are exemplary and non-limiting.

With an electrical energy storage device having a degraded SOH, many ofthe same conditions apply relative to the aged electrical energy storagedevice. In certain embodiments, the expected applications and expectedloads indicate that the target SOC is increased for an electrical energystorage device having a degraded SOH. In other embodiments, the expectedapplications and expected loads indicate that the target SOC isdecreased for an electrical energy storage device having a degraded SOH.All described behaviors are exemplary and non-limiting.

In certain embodiments, the technique includes determining the targetSOC in response to an electrical energy storage device throughput limit.An exemplary operation includes determining that charging or dischargingthe electrical energy storage device will exceed a throughput limit forthe electrical energy storage device, and the technique includestrimming the target SOC until the throughput limit is not exceeded. Incertain operations, the technique includes determining that the drawfrequency and amount from the electrical energy storage device greatlyexceeds the electrical energy storage device throughput limit, and thetechnique includes increasing the target SOC to build up a reserve ofpower, or decreasing the target SOC to build up a reserve ofregenerating capacity. In certain embodiments, in response to theelectrical energy storage device being reached or exceeded, thetechnique includes adjusting the target SOC such that the charging ordischarging rate is brought within the limits of the electrical energystorage device. All described behaviors are exemplary and non-limiting.

In certain embodiments, the technique includes determining the targetSOC in response to a first electrical torque provider throughput limit.The first electrical torque provider provides charging to the electricalenergy storage device when the hybrid power train operates in a seriesconfiguration. In certain embodiments, the technique includes adjustingthe target SOC such that a charging rate of the electrical energystorage device does not exceed the first electrical torque providerthroughput limit. In certain embodiments, the technique includesdetermining that the draw frequency and amount from the electricalenergy storage device greatly exceeds the first electrical torqueprovider throughput limit, and the technique includes increasing thetarget SOC to build up a reserve of power, or decreasing the target SOCto build up a reserve of regenerating capacity. All described behaviorsare exemplary and non-limiting.

In certain embodiments, the technique includes determining the targetSOC in response to a second electrical torque provider throughput limit.The technique including determining the target SOC in response to thesecond electrical torque provider throughput limit operates with similarconsiderations related to those described with respect to the firstelectrical torque provider throughput limit preceding.

In certain embodiments, the technique includes determining the targetSOC in response to an operator braking behavior. Exemplary operations todetermine the target SOC in response to the operator braking behaviorinclude lowering the target SOC to provide a reserve of regenerativecapacity in response to frequent operator braking behavior at a levelthat provides efficient regeneration opportunity. Another exemplaryoperation includes providing a target SOC that optimizes the health ofthe electrical energy storage device in response to operator brakingbehavior that is infrequent and/or that provides little regenerationopportunity. All described behaviors are exemplary and non-limiting.

A further exemplary technique includes determining a SOH of theelectrical energy storage device, and further adjusting the response tothe SOC deviation in response to the SOH. An exemplary operationincludes increasing the response to the SOC deviation in response to theSOH being reduced. An exemplary technique includes adjusting a responseto the SOC deviation in response to an operating temperature of theelectrical energy storage device, for example increasing a response tothe SOC deviation in response to a lower operating temperature.

An exemplary technique includes operating a closed loop controllerhaving the SOC deviation as an error value, where the closed loopcontroller includes an integral control term. The closed loop controlleraccordingly brings the SOC to the target SOC according to the responseprovided by the closed loop controller. In certain embodiments, thetarget SOC is updated to provided periodic charge or discharge of theelectrical energy storage device, and/or to allow the system to make afuel efficient adjustment by discharging the electrical energy storagedevice to avoid an inefficient operation elsewhere in the system, and/orto charge the electrical energy storage device to recover energy that ismade available elsewhere in the system.

Generally, the closed loop controller has a relatively long responsetime to allow the system to realize the benefits of the hybrid system byutilizing the electrical energy storage to smooth inefficient transientoperation. A relatively long response time depends upon the system,especially the duty cycle of the application, and the number andseverity of transient operations in the system. A highly transientsystem may have a wider range of SOC target values and a relativelyresponsive closed loop controller. A system with few transients and longperiods of steady state operation may have a narrower range of SOCtarget values and a relatively soft closed loop controller. Thedescribed closed loop controller is exemplary and non-limiting.

Another exemplary technique includes adjusting the SOC deviation and/ora response to the SOC deviation, in response to the machine powerdemand. In certain embodiments, a lower machine power demand indicates amore aggressive response to the SOC deviation, and a higher machinepower demand indicates a softer response to the SOC deviation. In theexemplary embodiment, when the machine power demand is high, theresponse to the SOC deviation is lowered such that operations to bringthe SOC to the target SOC do not interfere with the systemresponsiveness. In certain further embodiments, the technique includesadjusting the SOC deviation and/or a response to the SOC deviation inresponse to a rate of change of the machine power demand. Where the rateof change of the machine power demand is high, an exemplary techniqueincludes reducing the response to the SOC deviation. A change in the SOCdeviation may be implemented for any operation that adjusts the responseto the SOC deviation—generally reducing the SOC deviation results in alower response to the SOC deviation.

A further exemplary technique includes, in response to the machine powerdemand being negative, increasing an SOC target for the electricalenergy storage device, where the SOC deviation is determined in responseto the SOC target. The operation to increase the SOC target allows thesystem to capture an opportunistic regeneration event and improveoverall fuel economy. An additional or alternative method includes, inresponse to the machine power demand being high, reducing an SOC targetfor the electrical energy storage device, where the state of chargedeviation is determined in response to the SOC target. The operation todecrease the SOC target allows the system to remain responsive to aparticular operator demand.

Yet another exemplary set of embodiments is a technique, including anoperation to determine a machine shaft torque demand and a machine shaftspeed, and in response to the machine shaft torque demand and themachine shaft speed, an operation to determine a machine power demand.The technique further includes an operation to determine a powerdivision description between an internal combustion engine, a firstelectrical torque provider, and a second electrical torque provider, andan operation to determine a hybrid power train configuration as one ofseries and parallel. The technique further includes an operation todetermine a baseline power division description in response to a vehiclespeed and the machine power demand. The technique further includes anoperation to determine a SOC deviation for an electrical energy storagedevice electrically coupled to the first electrical torque provider andthe second electrical torque provider, and adjusting the baseline powerdivision description in response to the SOC deviation and the hybridpower train configuration.

The exemplary technique further includes an operation to determine theSOC deviation for the electrical energy storage device by determining adifference between a present SOC and a target SOC. A further embodimentincludes adjusting the SOC deviation in response to a present vehiclespeed, a temperature of the electrical energy storage device, astate-of-health of the electrical energy storage device, the machinepower demand, and/or an integrated state-of-charge deviation over time.

In certain embodiments, the baseline power division description includesa total electrical contribution and a total engine contribution, and thetechnique further includes, in response to determining the hybrid powertrain configuration is parallel, adjusting the baseline power divisiondescription by dividing the total electrical contribution in response tothe machine shaft speed. A further embodiment includes determining a netpower flux to the electrical energy storage device in response to theSOC deviation, where the adjusting the baseline power divisiondescription is in response to the net power flux. Additionally oralternatively, the technique includes dividing the total electricalcontribution in response to a first efficiency of the first electricaltorque provider at the machine shaft speed and a second efficiency ofthe second electrical torque provider at the machine shaft speed.

An exemplary technique further includes, in response to determining thehybrid power train configuration is parallel, adjusting the baselinepower division description by commanding the second electrical torqueprovider to achieve the machine power demand, commanding the firstelectrical torque provider to provide a net power flux to the electricalenergy storage device, and commanding the internal combustion engine topower the first electrical torque provider.

Yet another exemplary set of embodiments is a technique, includingoperating a hybrid power train having an internal combustion engine andone or more electrical torque providers. The technique further includesdetermining a machine power demand for the hybrid power train,determining a power division between the internal combustion engine andthe electrical torque provider in response to the machine power demand,determining a state-of-charge (SOC) of an electrical energy storagedevice electrically coupled to the at least one electrical torqueprovider, and interpreting a target SOC for the electrical energystorage device in response to a vehicle speed. The technique furtherincludes determining an SOC deviation for the electrical storage device,where the SOC deviation includes a function of a difference between theSOC of the electrical energy storage device and the target SOC of theelectrical energy storage device. The technique further includesadjusting the power division in response to the SOC deviation.

In further embodiments, the technique includes decreasing the target SOCin response to an increasing vehicle speed. An exemplary techniqueincludes adjusting the target SOC in response to a temperature of theelectrical energy storage device. A further exemplary technique includesdecreasing the target SOC in response to a decreasing temperature of theelectrical energy storage device. In certain embodiments, the techniqueincludes adjusting one of the target SOC and the SOC deviation inresponse to a state-of-health of the electrical storage device.

Yet another exemplary embodiment includes adjusting a cost of the SOCdeviation in response to a state of health of the electrical energystorage device. In certain embodiments, the technique includes operatinga cost function utilizing an engine cost function and an electrical costfunction to determine the power division between the engine and theelectrical torque provider(s), and further applying the cost of the SOCdeviation to adjust the power division and/or to determine a net powerflux to the electrical energy storage device. An exemplary techniquefurther includes increasing a cost of the SOC deviation in response to adecreased state of health of the electrical energy storage device.

In certain embodiments, the system includes a first electrical torqueprovider and a second electrical torque provider, and the power divisionis either an engine contribution and a total electrical contribution, orthe engine contribution, the first electrical torque providercontribution, and the second electrical torque provider contribution.where the power division is the engine contribution and a totalelectrical contribution, the technique includes an operation todetermine the first electrical torque provider contribution, and thesecond electrical torque provider contribution from the total electricalcontribution in response to the efficiencies of the first electricaltorque provider and the second electrical torque provider at presentoperating conditions.

In certain embodiments, the technique includes determining the SOCdeviation as a function of vehicle mass, electrical energy storagedevice capacity, an electrical energy storage device power limit (e.g.power throughput, influx current, effluent current, etc.), a torquecapacity of an electrical torque provider, a power capacity of anelectrical torque provider, and/or a detected operator braking behavior.In certain embodiments, where a torque capacity or a power capacity ofan electrical torque provider is utilized to determine the SOCdeviation, the SOC deviation is adjusted and/or a response to the SOCdeviation is adjusted such that the constraint of the torque capacity orpower capacity is maintained. In certain additional or alternativeembodiments, where the excess or deficient torque or power can beprovided or absorbed by another torque provider (e.g. the engine oranother electrical torque provider), the SOC deviation may be met andthe constraint of the torque capacity or power capacity is alsomaintained. In certain embodiments, for example according to the costfunctions of the engine, the electrical torque providers, and the SOCdeviation cost, some adjustment of the SOC deviation is provided andsome excess or deficient torque or power is provided or absorbed.

Yet another embodiment includes determining the SOH of the electricalenergy storage device in response to a throughput event of theelectrical energy storage device, a SOC event of the electrical energystorage device (e.g. the SOC reaching a high or low SOC thresholdvalue), a regeneration cycle event of the electrical energy storagedevice, and/or an age of the electrical energy storage device. Thetechnique includes modeling a SOH of the electrical energy storagedevice and/or applying rules to the estimated SOH of the electricalenergy storage device.

For example, a throughput event of the electrical energy storage device(e.g. a very high draw current from a battery) may be known to cause afailure in a known number of events, and/or a known average degradationover a number of events. Accordingly, a SOH effect of a singlethroughput event may be accumulated with other wear indicators toprovide an estimate of the SOH. In another example, an SOC event of theelectrical energy storage device may be known to cause a failure in aknown number of events, and/or a known average degradation over a numberof events. In the example, a very low SOC event may be noted and the SOHincremented, and/or an overcharge event of the electrical energy storagedevice may be noted and the SOH incremented.

In another example, the electrical energy storage device may beunderstood to experience a known amount of life loss per regenerationcycle—for example and without limitation tracked by triggering a firstcontrol flag at a threshold low SOC, and by triggering a second controlflag at a subsequent threshold high SOC to indicate that a regenerationcycle has occurred. Each regeneration cycle may be deemed to incrementthe electrical energy storage device SOH by a predetermined amount.

In yet another example, the electrical energy storage device may beunderstood to experience a loss in the SOH over time. For example, andwithout limitation, the electrical energy storage device may be abattery having a known loss with time, that may further be a function ofthe battery temperature. Accordingly, an accumulated aging amount may beadded to the SOH accumulation from one or more of the other indicatorsfor the SOH. The aging amount may be determined according to anyresolution available from input data (i.e. baseline aging data) andmeasured environment data (e.g. time and average temperature) for theelectrical energy storage device. For example, a daily or hourly agingaccumulation may be applied, or a monthly or yearly aging accumulationmay be applied.

An exemplary technique includes determining the power division and theadjusting the power division by operating a cost comparison algorithmbetween achieving the machine power demand with the internal combustionengine and the electrical energy storage device(s). The exemplarytechnique may further adjust the power division by operating the costcomparison algorithm including a cost of the SOC deviation. The SOCdeviation cost may be set to apply the desired balance of SOC targetingand operational responsiveness. Additionally or alternatively, anincremental cost to the SOH may be calculated from the current effectsof an SOC deviation on the electrical energy storage device SOH, andconverted into the same units as the engine cost function and electricalcost function. In one example, if the SOH accumulates to 100,000 toindicate that he electrical energy storage device requires replacement,and the electrical energy storage device costs $10,000 to replace, eachincremental unit of the SOH can be equated to $0.10. The provide exampleis not specific to any system, but the cost of replacement for anelectrical energy storage device, including the cost of service,downtime, and/or warranty costs, are understood to one of skill in theart contemplating a particular system.

Yet another exemplary set of embodiments is a technique, includingoperating a hybrid power train including an internal combustion engineand one or more electrical torque providers. The technique furtherincludes determining a machine power demand and, in response to themachine power demand, determining a power division description. Thetechnique further includes, in response to the power divisiondescription, operating the internal combustion engine and the at leastone electrical torque provider, where operating the internal combustionengine includes starting the internal combustion engine in response todetermining a battery SOC is about to fall below a limit.

Determining the battery SOC is about to fall below a limit includesestimating a time to fall below the limit at current usage anddetermining whether the estimated time is below a threshold. The time isselected according to the certainty of the battery SOC estimate, theextra power capacity of the system when operating on the internalcombustion engine, and the preferences of the operator of the particularsystem. In certain embodiments, time values of 30 seconds, one minute,five minutes, or ten minutes, without limitation, may be utilized. Incertain embodiments, determining the battery SOC is about to fall belowa limit includes determining that the battery SOC is below a secondlimit (higher than the first limit) and that a rate of discharge isgreater than a threshold value. The selection of the limit for thebattery SOC may be any limit understood in the art, including apredetermined charge amount, a charge amount capable of providing themachine power demand for a predetermined period of time, and/or a limitselected to ensure enough power remains to start the engine (potentiallyfurther corrected for the power draw that will be available undercurrent ambient conditions, or a conservatively determined set ofambient conditions).

In certain embodiments, the technique includes performing engineshutdown and engine startup operations with at least one time hysteresisvalue. The engine shutdown operation may include a first time hysteresisvalue (e.g. the engine must run for at least two minutes before asubsequent shutdown) and the engine startup operation may include asecond time hysteresis value (e.g. the engine must be shut down for atleast five minutes before a subsequent startup). The selected startupand shut down times are determined according to any criteria desired,including operator convenience or expectation, total start/stop cyclesdesired over the life cycle of the system, and/or any operationalparameters such as system temperatures, oil pressures, or otherparameters where it may be desirable to avoid rapid start/stop cycles ofthe engine.

An exemplary technique includes determining an engine shutdown timehysteresis value in response to a turbocharger temperature. For example,where a turbocharger temperature is elevated, it is undesirable to shutdown the engine rapidly, and accordingly a shut down timer may beimplemented to provide time for the turbocharger to cool before theengine is shut down. Further exemplary embodiments include determining aturbocharger temperature value, and preventing the engine shutdownoperation in response to the turbocharger temperature value exceeding athreshold. The temperatures at which thermal wear or damage can occur tothe turbocharger are understood to one of skill in the art contemplatinga particular system.

In certain embodiments, the technique includes determining that anengine shutdown operation is requested and/or imminent, and thetechnique further includes performing an engine-based turbochargercooldown operation in response to the requested or imminent engineshutdown operation. The engine-based turbocharger cooldown operationincludes operating the engine for a period of time before the shutdown,operating the engine at a reduced load value for a period of time,operating the engine at an operating condition selected to cool theturbocharger for a period of time, and/or operating the engine until theturbocharger temperature cools to a threshold level.

Certain exemplary embodiments include operating the internal combustionengine by starting the internal combustion engine in response todetermining that a power demand is about to exceed an electrical limit.The electrical limit may be a power or torque limit of one of theelectrical torque providers, a throughput limit of the power electronicsof one of the electrical torque providers, and/or a throughput limit ofan electrical bus of the system, where the bus communicates electricitybetween the battery, the electrical torque providers, and/or vehicleaccessories. When the internal combustion engine starts, the internalcombustion engine can provide some of the machine power demand andrelieve the electrical limit that is about to be exceeded. Thedetermination of when the electrical limit is about to be exceeded is amechanical step for one of skill in the art having the benefit of thedisclosures herein. In certain embodiments, the system reserves enoughcapacity before the electrical limit is exceeded such that the enginecan be started within the electrical limit while meeting the machinepower demand.

Another exemplary embodiment includes determining that a batterythroughput limit is about to be exceeded. The battery provides ongoingpower to the accessories and to the electrical torque providers. Whenthe battery throughput is about to be exceeded, the engine startingrelieves some of the torque burden of the electrical torque providerswhich then relieves the battery throughput limit. In certainembodiments, where accessory draw alone may exceed a battery throughputlimit, the engine can power the second electrical torque provider in agenerating mode to provide power to the electrical bus and relieve thebattery. The determination of when the battery throughput limit is aboutto be exceeded is a mechanical step for one of skill in the art havingthe benefit of the disclosures herein. In certain embodiments, thesystem reserves enough capacity before the battery throughput limit isexceeded such that the engine can be started within the batterythroughput limit while meeting the machine power demand.

In certain embodiments, a technique includes determining that a powerdemand rate of increase exceeds a limit. In certain embodiments, thepower demand rate of increase is high enough that, although anelectrical limit is not imminent, the engine is started to ensure thatthe machine power demand can be met even if the power demand rate ofincrease persists. The threshold power demand rate of increase thatindicates an engine start is selected according to the preference of oneof skill in the art, but an exemplary non-limiting value includes avalue consistent with a threshold power event such as that observed witha hill climb or merging event, and/or a threshold power request such asan accelerator pedal pressed past 80% or other selected value.

In certain embodiments, the technique includes operating the internalcombustion engine by starting the internal combustion engine in responseto determining that a battery SOC is below a threshold and/ordetermining that a power demand is above a threshold. An exemplarytechnique further includes determining an engine start capability indexof an electrical torque provider, and operating the internal combustionengine by starting the internal combustion engine in response to theengine start capability index being below a first threshold.

The engine start capability index may be determined from any criteriaknown in the art, including without limitation, an excess powerdeliverability of the second electrical torque provider, an excess powerdeliverability of the power electronics corresponding to the secondelectrical torque provider, and/or an excess battery throughputdeliverability to the second electrical torque provider. Where an excesspower deliverability is less than a threshold greater than a powerrequired to start the engine, the technique includes starting theengine. Where the excess power deliverability is degrading and thesystem is imminently going to be unable to start the engine, thetechnique includes starting the engine. For example, the techniqueincludes operating the internal combustion engine by starting theinternal combustion engine in response to determining that the enginestart capability index is about to fall below a second threshold. Anysystem parameter affecting the excess power deliverability may beutilized to determine the excess power deliverability, including atleast a maximum torque or power output of the second electrical torqueprovider relative to the machine power demand and the available torqueor power from the first electrical torque provider, a temperature of thesecond electrical torque provider, a temperature of the powerelectronics corresponding to the second electrical torque provider,and/or a temperature of the battery.

In certain embodiments, the technique includes allowing an internalcombustion engine shutdown in response to the hybrid power trainoperating in a series mode. An exemplary technique includes preventingan internal combustion engine shutdown in response to the internalcombustion engine operating in a thermal management mode and/or awarm-up mode. The warm-up mode may be determined according to the enginerecently starting after a predetermined period of time, according to anoil temperature and/or an engine coolant temperature, and additionallyor alternatively according to an ambient temperature being below athreshold value. The thermal management mode may be determined accordingto an aftertreatment component being in an active regeneration state, asystem component downstream of the engine requesting a temperaturevalue, and/or according to a control state of the system marking theengine as being in a thermal management mode.

Yet another exemplary set of embodiments is a system. The systemincludes a hybrid power train having an engine, a first electricaltorque provider, and a second electrical torque provider, and a loadmechanically coupled to the hybrid power train. The hybrid power trainfurther includes a clutch coupled to the engine and the secondelectrical torque provider on a first side, and coupled to the firstelectrical torque provider and the load on a second side. The systemfurther includes an electrical energy storage device electricallycoupled to the first electrical torque provider and the secondelectrical torque provider, and a controller structured to functionallyexecute operations to control the hybrid power train. The controllerimplements a time-based hysteresis on clutch engage-disengage.

In certain embodiments, the controller further smooths torque and/orpower commands for the engine and the second electrical torque providerin response to determining that a clutch engage-disengage event is oneof occurring or imminent. An exemplary operation to smooth the torqueand/or power commands includes applying a rate limiter and/or a low-passfilter to the engine and/or electrical torque provider torque and/orpower commands. In certain embodiments, the controller performs thesmoothing with a time constant that is fast relative to a highlytransient operator torque request. For example, where the system shouldrespond within 200 milliseconds to an operator request from 0% to 100%torque, the controller applies a time constant that is lower than 200milliseconds to the torque/power commands. An exemplary embodimentincludes providing the system time constant at about 5 times theexpected response (i.e. about 40 milliseconds in the example), althoughslower responding times are also contemplated herein, including timeconstants at about 2 times or 3 times the expected response.

The determination that a clutch engage-disengage event is occurring orimminent may be determined according to a very rapid change in adifference between a first shaft coupled to the engine and the secondelectrical torque provider and a second shaft coupled to the firstelectrical torque provider and the load. Additionally or alternatively,the determination that the clutch engage-disengage event is occurringincludes tracking a clutch position signal.

In certain embodiments, the controller provides a zero torque command tothe second electrical torque provider in response to one of a clutchengaging event and/or a clutch disengaging event.

In certain embodiments, the system includes the first shaft coupling theclutch to the engine and the second electrical torque provider, and thesecond shaft coupling the clutch to the first electrical torque providerand the load. The exemplary controller closes the clutch in response todetermining whether a speed of the first shaft is within a predeterminedspeed threshold value of a speed of the second shaft. An exemplarysystem further includes the controller operating a closed loopcontroller on a position of the clutch, where the clutch position errorvalue is determined in response to a difference between the speed of thefirst shaft and the speed of the second shaft. The clutch responding tothe closed loop controller is, in one embodiment, a non-binary clutchhaving multiple engagement values between fully open and fully closed.In certain embodiments, the closed loop controller includes an integralerror term.

Yet another exemplary set of embodiments is a technique, includingoperating a hybrid power train including an internal combustion engine,one or more electrical torque providers, and an electrical energystorage device electrically coupled to the electrical torqueprovider(s). The technique further includes determining a machine powerdemand, and in response to the machine power demand, determining a powerdivision description. In certain embodiments, the technique furtherincludes interpreting a SOH for the electrical energy storage device,and adjusting the power division description in response to the SOH forthe electrical energy storage device.

In certain embodiments, the technique further includes determining a SOCtarget for the electrical energy storage device in response to the SOHfor the electrical energy storage device, and further adjusting thepower division description in response to the SOC target for theelectrical energy storage device. An exemplary technique furtherincludes determining the SOC target in response to a charging energyefficiency for the electrical energy storage device. A still furtherexemplary technique includes determining the SOC target in response to acharge-discharge energy cycle efficiency for the electrical energystorage device.

In certain embodiments, the technique includes determining a dischargerate limit for the electrical energy storage device, and furtheradjusting the power division description in response to the dischargerate limit. An exemplary technique further includes determining thedischarge rate limit in response to a SOH of the electrical energystorage device, a power bus deliverability value, a motor limit for anelectrical torque provider, and/or an accessory load value. Theaccessory load value is the amount of energy or power the accessoriesare presently drawing from the electrical bus and/or the electricalenergy storage device. Another exemplary technique includes determiningthe discharge rate limit in response to a power electronics throughputlimit, where the power electronics is positioned between the electricalenergy storage device and an electrical torque provider.

An exemplary technique further includes determining a charge rate limitfor the electrical energy storage device, and further adjusting thepower division description in response to the charge rate limit. A stillfurther exemplary technique includes determining the charge rate limitin response to a SOH of the electrical energy storage device, a powerbus deliverability value, a motor limit for one of the electrical torqueproviders, and/or an accessory load value. In certain embodiments, thetechnique further includes determining the discharge rate limit inresponse to a power electronics throughput limit, where the powerelectronics is positioned between the electrical energy storage deviceand an electrical torque provider.

Yet another exemplary set of embodiments is a technique, includingoperating a hybrid power train including an internal combustion engineand one or more electrical torque providers, determining a machine powerdemand, determining an audible noise limit value for the internalcombustion engine, and determining a power division description inresponse to the machine power demand and the audible noise limit value.The technique further includes operating the internal combustion engineand the electrical torque provider(s) in response to the power divisiondescription. An exemplary technique further includes interpreting anoise input signal, and determining the audible noise limit value inresponse to the noise input signal. The noise input signal may beprovided by a user input. An exemplary user input include a switch witha high/low noise setting, which may be tied to other system controlssuch as a switch that disables compression braking in an urbanenvironment. In certain embodiments, the technique includes interpretingthe noise input signal as a response to a vehicle being in a reversegear, for example providing a minimum noise level in response to thevehicle being in the reverse gear. The described user inputs areexemplary and non-limiting.

In certain embodiments, the audible noise limit value is a maximum noiselevel and/or a minimum noise level. An exemplary technique includesdetermining the power division in response to the audible noise limit bylimiting a rate of change of engine power output. The limiting of therate of change of the engine power output includes a maximum rate ofchange and/or a minimum rate of change to provide engine operationconsistent with the maximum or minimum audible noise level. In certainembodiments, the technique includes determining the audible noise ratelimit value for the internal combustion engine, and adjusting the powerdivision description in response to the audible noise rate limit value.For example, a high noise level may be acceptable, but a high rate ofchange of the noise level may be undesirable, and the technique includeslimiting the audible noise rate limit value accordingly.

Yet another exemplary set of embodiments is a procedure for calibratinga hybrid power train control, and for controlling the hybrid powertrain. The procedure includes an operation to define an applicationoperating cycle, and an operation to define a number of behaviormatrices for a hybrid power train that powers the application. Eachbehavior matrix corresponds to operations of the hybrid power trainoperating in a parallel configuration, where the operations of the powertrain include operations of the power providing components that form aportion of the hybrid power train. The power providing componentsinclude an internal combustion engine and at least one electrical torqueprovider. For example, an exemplary behavior matrix includes a powercontribution for an internal combustion engine and an electrical systemas a function of a machine power demand and a machine shaft speed. Thepower contribution for the electrical system may be a single powercontribution for the entire electrical system, or a specific powercontribution for each electrical torque provider within the electricalsystem.

Where the behavior matrix provides the single power contribution for theentire electrical system, another procedure may be utilized downstreamto determine the optimal contributions from each of the electricaltorque providers to achieve the single power contribution for the entireelectrical system. In certain embodiments, when the hybrid power trainis operating in a series configuration, a first electrical torqueprovider provides the entire machine power demand, and the internalcombustion engine provides power to maintain a battery or electricalenergy storage device SOC.

The procedure further includes determining a number of behaviorsequences, where each behavior sequence corresponds to one of thebehavior matrices and includes a sequential set of values created fromthe corresponding behavior matrix applied sequentially to theapplication operating cycle. For example, the application operatingcycle includes a sequential series of machine power demand and machineshaft speed values over a period of time, and the behavior sequence isthe resultant sequential set of values created by applying thecorresponding behavior matrix to the application operating cycle. Theapplication operating cycle can be determined by any method understoodin the art, including at least providing a model application operatingcycle and/or determining the application operating cycle from GPS valuesfor a contemplated driving route.

The procedure further includes confirming a feasibility of each of thebehavior sequences, and determining a fitness value corresponding toeach of the feasible behavior sequences. The exemplary procedureincludes confirming the feasibility of each behavior sequence bydetermining whether an electrical limit is exceeded in the correspondingbehavior sequence. For example, if a battery SOC range is exceeded (highor low), a torque or power output of one of the electrical torqueproviders is exceeded, and/or a power throughput of the battery or powerelectronics is exceeded, the behavior sequence is determined to be notfeasible. In certain embodiments, the battery SOC is not utilized todetermine the feasibility of the behavior sequence.

Another exemplary procedure includes an operation to confirm thefeasibility of each behavior sequence by determining whether anemissions limit is exceeded in the corresponding behavior sequence. Theemissions limit may be an aggregate limit (e.g. a certain amount of NOxper power-time utilized in the behavior sequence), a specific limit(e.g. operation at a disallowed point or emissions output), excessiveoperation in a designated NTE zone, or other limit understood in theart.

In certain additional or alternative embodiments, the procedure includesconfirming the feasibility of each behavior sequence by determiningwhether an aftertreatment regeneration capability is provided in thecorresponding behavior sequence. Determining whether the aftertreatmentregeneration capability is provided includes determining whetheraftertreatment regeneration conditions are provided by the behaviorsequence, whether other operations of the system could provide theaftertreatment regeneration conditions during the behavior sequence,and/or whether the behavior sequence otherwise provides conditions suchthat an aftertreatment regeneration is not required. Any other operationknown in the art to determine whether the behavior sequence is feasiblein light of a contemplated aftertreatment system is understood to beincluded herein.

The operation to determine the fitness function of the feasible behaviorsequences includes, in one example, determining a cost parametercomprising the aggregate cost of the behavior sequence. The costparameter may be determined in currency units (e.g. dollars), emissionsunits, fuel consumption units, and/or as a unitless index value.Further, an exemplary operation includes determining ancillary costs andapplying those to the fitness function. For example, where modifiedengine operations are required to achieve aftertreatment regeneration, apro-rated aftertreatment regeneration cost is applied to the fitnessfunction. In a further example, if the behavior sequence provides 20% ofthe particulates that are required before a particulate filter must beregenerated (i.e. after five executions of the behavior sequence, theparticulate filter would require regeneration), and the exhausttemperatures of the engine are such that an amount of assistance isrequired to successfully achieve the regeneration, then ⅕^(th) of thecost of the amount of assistance is applied to the fitness function forthe behavior sequence. One of skill in the art, having the benefit ofthe disclosures herein, can construct a fitness function that optimizesthe parameter of interest, or the weighted set of parameters ofinterest, for the system.

The procedure further includes an operation to determine whether aconvergence value indicates that a successful convergence has occurredin response to the fitness value corresponding to each of the feasiblebehavior sequences. An exemplary determination of whether theconvergence value indicates a successful convergence is determining thata best fitness function from the set of fitness functions correspondingto the behavior sequences is more favorable than a threshold fitnessvalue. Another exemplary determination of whether the convergence valueindicates a successful convergence is determining that a best fitnessfunction from a generation of the behavior sequences is less than athreshold value more favorable than a a best fitness function from aprevious generation of behavior sequences. Yet another exemplarydetermination of whether the convergence value indicates a successfulconvergence is determining that a predetermined number of generations ofthe behavior sequences have provided less than a threshold value ofprogress in a best fitness function.

The best fitness function may be replaced with an average fitnessfunction, or an average of a subset of the best fitness functions, or byother parameters determined in response to the fitness functions of ageneration of behavior sequences. The described operations fordetermining a convergence value are exemplary and non-limiting. Anyconvergence determination or algorithm understood in the art iscontemplated herein.

Where the successful convergence has not occurred, the procedureincludes determining a number of child behavior matrices in response tothe number of behavior matrices, confirming the feasibility of each ofthe child behavior sequences resulting from the child behavior matrices,and determining the fitness value corresponding to each of the feasiblechild behavior sequences. The procedure further includes determiningagain whether the convergence value indicates that the successfulconvergence has occurred, in response to the fitness value correspondingto each of the feasible child behavior sequences.

An exemplary procedure includes determining a number of child behaviormatrices by selecting a number of parent behavior matrices from thebehavior matrices in response to the corresponding fitness functions. Afurther exemplary procedure includes selecting parent behavior matricesby selecting the most fit behavior matrices, and/or selecting behaviormatrices having a survival probability related to the correspondingfitness function. Each parent behavior matrix may produce one child, ormore than one child, with the number of child behavior matrices furtherdetermined according to the fitness function of the parent behaviormatrix. Each child may likewise include any number of parent matrices,with an exemplary number of parent matrices being two. In certainfurther embodiments, the procedure includes crossing over behaviorparameters between two or more parent behavior matrices to determine achild behavior matrix. In certain further embodiments, the procedureincludes applying a random change to a parameter of the child behaviormatrix.

The rate of random change (i.e. mutations) and the number of parameterssubject to mutation are selectable parameters. A higher mutation ratemay provide a faster convergence and be more resilient to behaviorsystems having many local minima. However, a mutation rate that is toohigh can cause an unstable solution progression and prevent convergence.One of skill in the art, having the benefit of the disclosures herein,can select appropriate values for the mutation rate to provide thedesired convergence time and overall optimization certainty. Where theconvergence time is too long, the mutation rate is decreased, and wherethe certainty of the optimization is in question, a number ofgenerations can be operated with an increased mutation rate.

Where the successful convergence has occurred, the procedure includesdetermining a calibration matrix in response to the behavior matricesand the fitness values. The calibration matrix is selected from thematrices—behavior matrices or child behavior matrices—that correspond tothe successful convergence check, i.e. the group of matrices from theconvergent generation. An exemplary operation includes selecting abehavior matrix having the best fitness function. The technique furtherincludes providing the calibration matrix to a hybrid power traincontroller, and operating a hybrid power train with the hybrid powertrain controller.

In an exemplary embodiment, the behavior matrices (the first generationand the child behavior matrices) include a number of hybrid power trainoperating conditions, and a behavior vector corresponding to each of thehybrid power train operating conditions. The behavior vector includes apower division description for the power providing devices. The powerdivision description includes a power contribution for an internalcombustion engine and a power contribution for an electrical system, ora power contribution for the internal combustion engine and a powercontribution for each of the electrical torque providers. In certainembodiments, the number of hybrid power train operating conditionsinclude a machine shaft speed and a machine power demand.

In certain embodiments, the power division description includes a totalelectrical contribution and an internal combustion engine contribution.In certain further embodiments, the power division description includesan internal combustion engine contribution, a power contribution of afirst electrical torque provider, and a power contribution of a secondelectrical torque provider.

In certain embodiments, each contribution includes a discrete number ofpossible states, and each behavior matrix includes the discrete numberof possible states corresponding to the contribution. In one example,the internal combustion engine contribution includes 1,024 statesbetween horsepower values from −600 hp to +475 hp (for example in anengine having a compression brake capable of 600 hp of braking power and475 hp of propulsion power), where the 1,024 states may be evenlydivided or divided by any other scheme understood in the art.

In certain further embodiments, the discrete number of possible statescorresponding may be varied as a characteristic changeable between abehavior matrix and a child behavior matrix, or a characteristicdiffering between two parent matrices and inheritable by the childmatrix, and/or as a mutatable parameter. Where the discrete number ofstates of the child behavior matrix differ from the discrete number ofstates of a parent behavior matrix, the child behavior matrix mayinclude interpolated or extrapolated values to approximate the parentbehavior matrix. Accordingly, the genetic algorithm further divides theengine and/or electric motors into a number of discrete operating states(e.g. power output values), and converges on the beneficial number ofthe discrete operating states. Additionally or alternatively, thefitness function may be constructed to implement a cost to the number ofoperating states (e.g. based on incremental computing cost from storinglarger power division description tables). In certain embodiments, thenumber of discrete operating states for the internal combustion engineis allowed to vary, but the number of discrete operating states for theelectrical system, and/or the number of discrete operating states foreach electrical torque provider is fixed.

In certain embodiments, the procedure includes determining whether theconvergence value indicates that the successful convergence has occurredby determining whether an incremental improvement in a characteristicfitness value is lower than a convergence threshold value. In certainembodiments, the characteristic fitness function includes a best fitnessvalue. In certain further embodiments, the method includes performing asensitivity check on a behavior matrix corresponding to the best fitnessvalue. An exemplary operation to perform a sensitivity check includesdetermining whether an incremental improvement in the characteristicfitness value exceeds an acute convergence threshold value.

In certain embodiments, the application operating cycle includes adriving route. Additional or alternative embodiments include theapplication operating cycle having a number of discrete driving routeshaving a similar duty cycle characteristic. In one example, a number ofsimilar urban delivery routes may be included, and the applicationoperating cycle includes the sum of the delivery routes (e.g. the routesplaced together sequentially).

In certain embodiments, the procedure includes determining a number ofcalibration matrices, each calibration matrix corresponding to one of anumber of application operating cycles, where each of the applicationoperating cycles corresponds to a distinct duty cycle characteristic.The distinct duty cycle characteristic is a characteristic known,expected, or observed to provide a distinct optimal hybrid power trainbehavior. For example and without limitation, a first duty cyclecharacteristic may be level road long haul trucking, a second duty cyclecharacteristic may be rolling hills combined with interspersed mountainclimbs and descents, and a third duty cycle characteristic may be aheavy load urban delivery route. Any selected duty cycle characteristicis contemplated herein.

In certain further embodiments, the procedure further includesdetermining a real-time duty cycle characteristic of the hybrid powertrain, and selecting one of a number of calibration matrices in responseto the real-time duty cycle characteristic, and further in response tothe distinct duty cycle characteristics corresponding to the observedapplication operating cycles during the operation of the hybrid powertrain. In certain embodiments, the procedure includes selecting one ofthe calibration matrices, and/or interpolating between two of thecalibration matrices in response to the real-time duty cyclecharacteristic and the distinct duty cycle characteristics correspondingto the application operating cycles.

In certain embodiments, the parallel configuration constrains theengine, the first electrical torque provider, and the second electricaltorque provider to operate at one of a uniform speed or at a fixed ratioof speeds. For example a gear positioned between the engine and thefirst electrical torque provider may constrain the first electricaltorque provider to operate at a fixed ratio relative to the engine.

An exemplary fitness value includes a fuel economy cost and/or anemissions cost. An exemplary fitness value further includes a secondarycost of emissions. An exemplary secondary cost of emissions includes aservice life cost of an aftertreatment device (e.g. an incrementalservice life lost due to subsequent regeneration increment to eliminatethe received emissions increment), an operating cost of theaftertreatment device (e.g. urea or NH₃ usage to respond to the receivedemissions), and/or an aftertreatment device regeneration cost of theaftertreatment device.

An exemplary procedure includes downloading run-time data of the hybridpower train to an external computer, selecting at least a portion of therun-time data as an application operating cycle, and generating a secondcalibration matrix in response to the run-time data. The externalcomputer includes a computer on-board a vehicle having the hybrid powertrain, and/or a computer external the vehicle having the hybrid powertrain.

In one example, the external computer is a fleet computer, and a fleetowner operates the calibration routine on the real run-time data of thecontroller after downloading the run-time data from the controller. Incertain embodiments, the system thereby responds to a change in thedriving route or drive cycle, including responses to a change in adriver, a change in a traffic pattern, a seasonal change in the drivingroute, and/or a change in the utilization of the vehicle. The downloadeddata, or a portion of the downloaded data, may be utilized after eachvehicle long cycle, for example every 10 days on a long haul vehiclethat averages 10 days away from the fleet home. Accordingly, theresponse time of the calibration of the controls is selectable in amanner that is sensible for the application, and that can respond withimproved controls within one driving route execution.

An exemplary procedure includes utilizing the original calibrationmatrix as a parent behavior matrix. The utilization of the originalcalibration matrix as a parent behavior matrix bounds, to an extent, theoutput of the updated calibration matrix and limits the amount of changeexperienced by a vehicle operator within a single update of thecalibration matrix. An additional or alternative embodiment includeslimiting an amount of change between the calibration matrix and thesecond calibration matrix. In certain embodiments, limiting the amountof change includes incrementally moving a current calibration matrix toa more optimal calibration matrix over a period of time, and/or onlypartially applying a more optimal calibration matrix to a currentcalibration matrix, and potentially re-checking the run-time data beforefurther changes in the calibration matrix.

In certain embodiments, the run-time data is compressed and stored on acontroller of the hybrid power train until the downloading. Anycompression operation known in the art is contemplated herein. Thecompression may be lossless, for example by lumping redundantspeed-power values, accessing externally available data with labelsrather than using the raw data such as labeling highway route data,and/or any other lossless compression known to one of skill in the arthaving the benefit of the disclosures herein. The compression may,alternatively or additionally, be lossy—for example providing timeaveraged samples of the data, providing Fourier compressed data values(or other similar compression mechanisms for sequential data), or by anyother method understood in the art. The use of compressed data allowsthe controller to provide the data to an external computer more rapidly,and further allows the data to be stored without taking up as muchmemory in the controller where, for embedded controllers, memory spaceis often at a premium.

Yet another exemplary set of embodiments is a system, including a hybridpower train having an internal combustion engine and an electricalsystem, the electrical system including a first electrical torqueprovider, a second electrical torque provider, and an electrical energystorage device electrically coupled to the first electrical torqueprovider and the second electrical torque provider. The system furtherincludes a controller structured to perform certain operations forcontrolling a hybrid power train.

The controller determines a power surplus value of the electricalsystem, determines a machine power demand change value, and operates anoptimum cost controller to determine a power division for the engine,first electrical torque provider, and second electrical torque providerin response to the power surplus value of the electrical system beinggreater than or equal to the machine power demand change value. Anexemplary controller further operates a rule-based controller todetermine the power division for the engine, first electrical torqueprovider, and second electrical torque provider in response to the powersurplus value of the electrical system being less than the machine powerdemand change value. In certain embodiments, the controller includesoperating the rule-based controller in response to the machine powerdemand change value exceeding a threshold, even where the firstelectrical torque provider has a power surplus value.

An exemplary system further includes the controller determining thepower surplus value of the first electrical torque provider in responseto the electrical system having power delivery availability to meet themachine power demand change value. The determination of power deliveryavailability may include determining that the first electrical torqueprovider has sufficient torque and/or power producing (or generating)capacity, a determination that power electronics for the firstelectrical torque provider have sufficient power transfer capability,and/or that the electrical energy storage device has sufficient charge,storage capacity, and/or power throughput available such that the firstelectrical torque provider can meet the machine power demand changevalue, or the machine power demand change value plus a threshold margin.

In certain embodiments, the controller determines the power surplusvalue in response to a torque rating of the first electrical torqueprovider, a torque rating of the second electrical torque provider, anaccessory load, a throughput rating of the electrical energy storagedevice, an SOC of the electrical energy storage device, a throughputrating of a first power electronics interposed between the electricalenergy storage device and the first electrical torque provider, and/or athroughput rating of a second power electronics interposed between theelectrical energy storage device and the second electrical torqueprovider.

In certain embodiments, the controller further operates the optimum costcontroller by incrementally changing a power provided by the engine in afirst execution cycle, and determining whether the incrementally changedpower improved a power cost value. An exemplary operation includesproviding the incremental change first in one direction, until a changein sign is observed in the rate of change of the power cost value, thenreversing the direction of the incremental change. In certainembodiments controller further applies a random noise value to theincrementally changing power provided by the engine. The random noisevalue may, in certain embodiments, reverse the direction of theincremental change, without changing the intended direction of theincremental change. For example, a present power division descriptionmay include 60% of the power provided by the internal combustion engineand 40% of the power provided by the electrical system, with thedirection of the incremental change being toward more power from theinternal combustion engine. In the example, a next execution cycle maynominally include an incremental change value of 1%, for an initial nextpower division description of 61% engine, 39% electrical. Where therandom noise value applies a 2% decrease to the engine powercontribution, the actually applied next power division description is59% engine, 41% electrical system, with the intended directioncontinuing to be toward more engine power unless the decrease in theengine power shows a better cost outcome.

The random noise value, in certain embodiments, includes an amplitudeselected in response to an expected local minima depth property of aresponse surface of the hybrid power train. The hybrid power trainincludes an operating cost surface that, in certain operatingconditions, is susceptible to local minima on the cost response. Forexample, a large number of variations in the operating conditions (e.g.wide variety of traffic patterns and geographic differences), and/or alarge number of devices having constraints (electric motor/generators,power electronics, internal combustion engine, battery and/or otherstorage devices) are indicators that local minima may be present.Devices having large differences between constrained or unconstrainedbehavior, and/or high turndown ratios (a large difference betweenminimal and maximal output) are indicators that local minima may besignificantly deep—deep enough that a standard incremental change amountmay walk over or be stuck within one of the local minima. Accordingly,the amplitude of the random noise value may be increased in situationswhere a large number of local minima, and/or local minima havingsignificant depth are indicated.

In certain embodiments, the controller increases an amplitude of theincremental change in response to an increasing rate of change of thepower cost value. For example, the controller determines the rate ofchange of the power cost value in response to an incremental change, andwhere the rate of change of the power cost value is increasing, thecontroller increases the amplitude of the incremental change. In afurther example, the controller increases the internal combustion enginecontribution from 25% to 28% of the machine power demand (a 3%incremental change). In a first exemplary response, the rate of changeof the power cost value increases from 20 units/second to 30units/second. Since the rate of change of the power cost value ispositive and increasing, the controller in the example increases theamplitude of the incremental change to a value greater than the 3%(subject to the random noise effects, where present). In a secondexemplary response, the rate of change of the power cost value increasesfrom −20 units/second to −30 units/second. Since the rate of change ofthe power cost value is negative and increasing, the controller in theexample increases the amplitude of the incremental change to a valuegreater than the 3%, and switches the sign of the incremental changesince the cost outcome is getting worse. The described responses areexemplary and non-limiting.

In certain further embodiments, the controller further operates theoptimum cost controller as a closed loop controller having an errorvalue determined in response to a slope of the power cost value withtime. In one example, the closed loop controller targets a slope of thepower cost value with time of zero, and more specifically a zero slopecorresponding to a minimum cost value or corresponding to a maximumbenefit value. An exemplary optimum cost controller includes aproportional-integral controller. In certain embodiments, the systemfurther includes the controller commanding the first electrical torqueprovider to meet the machine power demand change value.

In certain embodiments, the controller operates the rule-basedcontroller by responding to increasing power demand by, in order anduntil the power demand is achieved, increasing power of the firstelectrical torque provider, increasing power of the second electricaltorque provider, and increasing power of the engine. In certainembodiments, the controller operates the rule-based controller byresponding to decreasing power demand by, in order and until the powerdemand is achieved, decreasing power of the first electrical torqueprovider, decreasing power of the second electrical torque provider, anddecreasing power of the engine. An exemplary controller further limitsthe first electrical torque provider and the second electrical torqueprovider to a minimum zero torque until the engine reaches a minimumtorque value during a decreasing power demand. Alternatively, theexemplary controller applies a maximum generating torque of the firstelectrical torque provider, then applies a maximum generating torque ofthe second electrical device during a decreasing power demand until thepower demand is achieved.

An exemplary system further includes a clutch positioned with the firstelectrical torque provider and a load on a first side and with theinternal combustion engine and the second electrical torque provider ona second side. The clutch in a closed position provides the hybrid powertrain in a parallel configuration, and the clutch in an open positionprovides the hybrid power train in a series configuration. An exemplarysystem further includes, in response to determining the clutch is openand the power surplus value is less than the machine power demand changevalue, the controller commanding the clutch to close. Another exemplarysystem includes, in response to determining the clutch is open and thepower surplus value is less than the machine power demand change value,and further in response to determining the clutch is disallowed fromclosing, the controller commanding the first electrical torque providerto one of a maximum or minimum torque position.

As is evident from the figures and text presented above, a variety ofembodiments according to the present invention are contemplated.

A first set of exemplary embodiments is a method, including determininga machine shaft torque demand and a machine shaft speed, and in responseto the machine shaft torque demand and the machine shaft speed,determining a machine power demand. The method further includes, inresponse to determining the machine shaft speed is zero and the machineshaft torque demand is greater than zero, adjusting the machine powerdemand to a non-zero value. The method further includes determining apower division description between an internal combustion engine and oneor more electrical torque providers, and operating the internalcombustion engine and the electrical torque providers in response to thepower division description.

Certain further exemplary embodiments of the method are describedfollowing. An exemplary method further includes determining an enginecost function that includes an engine operating cost as a function ofengine power output, determining an electrical cost function thatincludes an electrical torque provider operating cost as a function ofthe electrical torque provider power output, where the method includesdetermining the power division description in response to the enginecost function and the electrical cost function. An exemplary embodimentfurther includes the electrical cost function having an efficiency ofcorresponding power electronics, where the power electronics areelectrically positioned between the corresponding electrical torqueprovider and an electrical energy storage device. The electrical costfunction may further include a generating operating region, and theelectrical cost function may include an electrical energy storageefficiency and/or an electrical energy storage efficiency and recoveryefficiency (i.e. the entire storage and recovery cycle efficiency).

An exemplary method further includes determining a second electricalcost function that includes a second electrical torque provideroperating cost as a function of a second electrical torque providerpower output, where the method includes determining the power divisiondescription further in response to the engine cost function, theelectrical cost function, and the second electrical cost function. Anexemplary second electrical cost function further includes an efficiencyof the power electronics corresponding to the second electrical torqueprovider. In certain embodiments, the second electrical cost functionincludes a generating operating region, and accounts for a secondstorage efficiency and/or a second storage and recovery cycleefficiency.

In certain embodiments, the method includes one or more hybrid powertrain operating modes. In a first operating mode, the method includesdisengaging a clutch between the internal combustion engine and thefirst electrical torque provider, and providing all of the machine powerdemand with the first electrical torque provider. In a second operatingmode, the method includes engaging the clutch between the internalcombustion engine and the first electrical torque provider and providingall of the machine power demand with the internal combustion engine. Ina third operating mode, the method includes engaging the clutch betweenthe internal combustion engine and the first electrical torque providerand dividing the machine power demand between the internal combustionengine and the first electrical torque provider. In a fourth operatingmode, the method includes engaging the clutch between the internalcombustion engine and the first electrical torque provider and dividingthe power between the internal combustion engine and the secondelectrical torque provider. In a fifth operating mode, the methodincludes engaging the clutch between the internal combustion engine andthe first electrical torque provider and dividing the power between thefirst electrical torque provider and the second electrical torqueprovider. In a sixth operating mode, the method includes engaging theclutch between the internal combustion engine and the first electricaltorque provider and dividing the power between the internal combustionengine, the first electrical torque provider, and the second electricaltorque provider.

Certain further exemplary embodiments include determining a costdisposition parameter, and determining each of the cost functions inresponse to the cost disposition parameter and a plurality ofcorresponding cost functions. For example, a first cost dispositionparameter corresponds to a first set of cost functions, a second costdisposition parameter corresponds to a second set of cost functions, andthe method includes determining whether the first cost dispositionparameter or the second cost disposition parameter is to be utilized inthe present application of the method. Exemplary cost dispositionparameter include a duty cycle category and/or a drive route parameter.Exemplary operations to determine each cost function in response to thecost disposition parameter include selecting the cost functionscorresponding to the cost disposition parameter, and interpolatingbetween two proximate cost functions according to the cost dispositionparameter.

Certain further embodiments of the method include adjusting the powerdivision description in response to an electrical storage devicestate-of-charge. An exemplary method includes determining the electricalcost function(s) that describe the electrical torque provider(s)operating cost as a function of the power output for the correspondingelectrical torque provider and further as a function of astate-of-charge for the electrical energy storage device.

In certain embodiments, the method includes determining a vehicle speed,and determining the power division description in response to themachine power demand and the vehicle speed. In a further embodiment, themethod includes determining a number of nominal power divisiondescriptions as a two-dimensional function of the vehicle speed and themachine power demand, and where determining the power divisiondescription further includes performing a lookup operation utilizing theplurality of nominal power division descriptions. For example, thelookup operation includes cross-referencing the vehicle speed andmachine power demand to a table having nominal power divisiondescriptions, and selecting the nominal power division descriptionclosest to the vehicle speed and machine power demand. The exemplarylookup operation may further include interpolating and/or extrapolatingin one or both dimensions.

Certain exemplary embodiments includes the power division descriptiondetermining the power division between the internal combustion engine, afirst electrical torque provider, and a second electrical torqueprovider. An exemplary method includes, in response to determining thatthe second electrical torque provider provides the entire machine torquedemand: disengaging a clutch positioned between the internal combustionengine and the second electrical torque provider.

In certain embodiments, the engine cost function includes an emissionscost for the engine—for example determined from the nominal emissions ofthe engine at the speed and torque indicated by the present engine speedand the contemplated power contribution of the engine. A furtherexemplary embodiment includes the engine cost function having a secondemissions cost. For example, the first engine emissions cost may bedetermined for NO_(x) emissions and the second engine emissions cost maybe determined for particulate emissions. In certain further embodiments,the engine cost function further includes a secondary effect cost.Exemplary and non-limiting secondary effect costs include an incrementallife loss of an aftertreatment component, and/or an incrementalregeneration cost of the aftertreatment component. In certain furtherembodiments, one or more of the emissions cost or secondary effect costsinclude a discontinuity in the cost function.

The described power division operations may be performed when themachine power demand is positive or negative, and any power provider inthe system may be providing power of a positive or negative magnituderegardless of the magnitude of the machine power demand. Exemplary andnon-limiting examples include the machine power demand being positive,with the internal combustion engine providing positive power and anelectrical torque provider providing negative power (e.g. to regeneratea battery). In certain embodiments, the power division descriptionincludes an engine braking target power value.

Another exemplary set of embodiments is a method, including determininga machine shaft torque demand and a machine shaft speed, and in responseto the machine shaft torque demand and the machine shaft speed,determining a machine power demand. The method further includesdetermining a power division description between an internal combustionengine, a first electrical torque provider, and a second electricaltorque provider, and determining a clutch position that is engaged ordisengaged. The descriptions herein utilize a clutch position, howeverunless stated explicitly to the contrary, certain embodiments determinewhether a hybrid power train is in a parallel arrangement or a serialarrangement, where the clutch engaged corresponds to the parallelarrangement and the clutch disengaged corresponds to the serialarrangement.

The clutch, for embodiments having the clutch, is interposed between thefirst electrical torque provider on a first side and the internalcombustion engine and the second electrical torque provider on a secondside. In certain further embodiments, a load is on the side of theclutch having the first electrical torque provider. The load receivesthe power output of the hybrid power train, and is at any positiondownstream of all power providing components in the hybrid power train.Exemplary and non-limiting loads include the drive wheels of a vehicle,a transmission tail shaft, a vehicle drive line, a power takeoff shaft,or a generator output shaft.

The exemplary method further includes determining a baseline powerdivision description in response to a vehicle speed and the machinepower demand. The vehicle speed, in certain embodiments, may besubstituted with a load kinetic energy description, such as a rotatingkinetic energy of a flywheel, rotating machine, etc. The method furtherincludes determining a state-of-charge deviation for an electricalenergy storage device, where the electrical energy storage device iselectrically coupled to the first electrical torque provider and thesecond electrical torque provider. The description herein includes asingle electrical energy storage device coupled to both electricaltorque providers, however except where explicitly stated to the contraryan electrical energy storage device may be coupled to only a singleelectrical torque provider. Further, additional electrical energystorage devices may be present in a given system, each device coupled toat least one electrical torque provider. For example, and withoutlimitation, a hyper-capacitor or ultra-capacitor may be incorporatedinto the electrical system and provide additional electrical energystorage capacity and electrical energy transient control.

The exemplary method further includes adjusting the baseline powerdivision description in response to the state of charge deviation andthe clutch position. In certain embodiments, determining thestate-of-charge deviation for the electrical energy storage deviceincludes determining a difference between a present state-of-charge anda target state-of-charge. In certain embodiments, the method includeadjusting a state-of-charge deviation in response to a present vehiclespeed, a temperature of the electrical energy storage device, astate-of-health of the electrical energy storage device, the machinepower demand, and/or an integrated state-of-charge deviation over time.

An exemplary baseline power division description includes a totalelectrical contribution and a total engine contribution, where theexemplary method further includes, in response to determining the clutchis engaged, adjusting the baseline power division description bydividing the total electrical contribution in response to the machineshaft speed. In certain embodiments, the method includes determining anet power flux to the electrical energy storage device in response tothe state of charge deviation, where adjusting the baseline powerdivision description is in response to the net power flux. In certainembodiments, dividing the total electrical contribution is in responseto a first efficiency of the first electrical torque provider at themachine shaft speed, and to a second efficiency of the second electricaltorque provider at the machine shaft speed.

An exemplary method further includes, in response to determining theclutch is disengaged, adjusting the baseline power division descriptionby commanding the second electrical torque provider to achieve themachine power demand, by commanding the first electrical torque providerto provide a net power flux to the electrical energy storage device, andby commanding the internal combustion engine to power the firstelectrical torque provider.

Several exemplary and non-limiting baseline power division descriptionsare providing following.

A first example includes a total electrical contribution and a totalengine contribution, where the total electrical contribution and thetotal engine contribution combined provide the machine power demand. Asecond example includes a power contribution for each of the internalcombustion engine, the first electrical torque provider, and the secondelectrical torque provider, where the total power contributions providethe machine power demand. A third example includes a total electricalcontribution, a total engine contribution, and a net power flux to theelectrical power storage device, where the total electricalcontribution, the total engine contribution, and the net power fluxcombine to provide the machine power demand.

A fourth example includes a power contribution for each of the internalcombustion engine, the first electrical torque provider, the secondelectrical torque provider, and a net power flux to the electrical powerstorage device, where the total power contributions and the net powerflux provide the machine power demand. A fifth example includes a totalelectrical contribution, a total engine contribution, a net power fluxto the electrical power storage device, and a net power flux toaccessories, where the total electrical contribution, the total enginecontribution, the net power flux to the electrical energy storagedevice, and the net power flux to the accessories combine to provide themachine power demand. A sixth example includes a power contribution foreach of the internal combustion engine, the first electrical torqueprovider, the second electrical torque provider, a net power flux to theelectrical power storage device, and a net power flux to accessories,where the total power contributions, the net power flux to theelectrical energy storage device, and the net power flux to theaccessories provide the machine power demand.

The exemplary method further includes reducing the state of chargedeviation and/or reducing a response to the state of charge deviation inresponse to an increasing vehicle speed. An exemplary embodimentincludes increasing a response to the state of charge deviation inresponse to a magnitude of the state of charge deviation, and/orincreasing a response to the state of charge deviation over time inresponse to the state of charge deviation being maintained. A furtherembodiment includes responding to the state of charge deviation with aproportional and/or integral response.

An exemplary method includes determining the state of charge deviationin response to a target SOC. The method includes determining the targetSOC in response to a vehicle speed, a vehicle mass, an electrical energystorage device capacity, an electrical energy storage device throughputlimit, a first electrical torque provider throughput limit, a secondelectrical torque provider throughput limit, and/or an operator brakingbehavior. A further exemplary method includes determining a state ofhealth of an electrical energy storage device, and further adjusting theresponse to the state of charge deviation in response to the state ofhealth. An exemplary operation includes increasing the response to thestate of charge deviation in response to the state of health beingreduced. An exemplary method includes adjusting a response to the stateof charge deviation in response to an operating temperature of theelectrical energy storage device, for example increasing a response tothe state of charge deviation in response to a lower operatingtemperature.

An exemplary method includes operating a closed loop controller havingthe state of charge deviation as an error value, where the closed loopcontroller includes an integral control term. Another exemplary methodincludes adjusting the state of charge deviation and/or a response tothe state of charge deviation, in response to the machine power demand.A further exemplary method includes in response to the machine powerdemand being negative, increasing an SOC target for the electricalenergy storage device, where the state of charge deviation is determinedin response to the SOC target. An additional or alternative methodincludes, in response to the machine power demand being high, reducingan SOC target for the electrical energy storage device, where the stateof charge deviation is determined in response to the SOC target.

Yet another exemplary set of embodiments is a method, includingdetermining a machine shaft torque demand and a machine shaft speed, andin response to the machine shaft torque demand and the machine shaftspeed, determining a machine power demand. The method further includesdetermining a power division description between an internal combustionengine, a first electrical torque provider, and a second electricaltorque provider, determining a hybrid power train configuration as oneof series and parallel, and determining a baseline power divisiondescription in response to a vehicle speed and the machine power demand.The method further includes determining a state-of-charge deviation foran electrical energy storage device electrically coupled to the firstelectrical torque provider and the second electrical torque provider,and adjusting the baseline power division description in response to thestate of charge deviation and the hybrid power train configuration.

The exemplary method further includes determining the state-of-chargedeviation for the electrical energy storage device by determining adifference between a present state-of-charge and a targetstate-of-charge. A further embodiment includes adjusting thestate-of-charge deviation in response to a present vehicle speed, atemperature of the electrical energy storage device, a state-of-healthof the electrical energy storage device, the machine power demand,and/or an integrated state-of-charge deviation over time.

In certain embodiments, the baseline power division description includesa total electrical contribution and a total engine contribution, and themethod further includes, in response to determining the hybrid powertrain configuration is parallel, adjusting the baseline power divisiondescription by dividing the total electrical contribution between thefirst electrical torque provider and the second electrical torqueprovider in response to the machine shaft speed. A further embodimentincludes determining a net power flux to the electrical energy storagedevice in response to the state of charge deviation, where the adjustingthe baseline power division description is in response to the net powerflux. Additionally or alternatively, the method includes dividing thetotal electrical contribution in response to a first efficiency of thefirst electrical torque provider at the machine shaft speed and a secondefficiency of the second electrical torque provider at the machine shaftspeed.

An exemplary method further includes, in response to determining thehybrid power train configuration is parallel, adjusting the baselinepower division description by commanding the second electrical torqueprovider to achieve the machine power demand, commanding the firstelectrical torque provider to provide a net power flux to the electricalenergy storage device, and commanding the internal combustion engine topower the first electrical torque provider.

Yet another exemplary set of embodiments is a method, includingoperating a hybrid power train having an internal combustion engine andoner or more electrical torque providers. The method further includesdetermining a machine power demand for the hybrid power train,determining a power division between the internal combustion engine andthe electrical torque provider in response to the machine power demand,determining a state-of-charge (SOC) of an electrical energy storagedevice electrically coupled to the at least one electrical torqueprovider, and interpreting a target SOC for the electrical energystorage device in response to a vehicle speed. The method furtherincludes determining an SOC deviation for the electrical storage device,wherein the SOC deviation comprises a function of a difference betweenthe SOC of the electrical energy storage device and the target SOC ofthe electrical energy storage device, and adjusting the power divisionin response to the SOC deviation.

In further embodiments, the method includes decreasing the target SOC inresponse to an increasing vehicle speed. An exemplary method includesadjusting the target SOC in response to a temperature of the electricalenergy storage device. A further exemplary method includes decreasingthe target SOC in response to a decreasing temperature of the electricalenergy storage device. In certain embodiments, the method includesadjusting one of the target SOC and the SOC deviation in response to astate-of-health of the electrical storage device. Yet another exemplaryembodiment includes adjusting a cost of the SOC deviation in response toa state of health of the electrical energy storage device. An exemplarymethod further includes increasing a cost of the SOC deviation inresponse to a decreased state of health of the electrical energy storagedevice.

In certain embodiments, the method includes determining the SOCdeviation as a function of vehicle mass, electrical energy storagedevice capacity, an electrical energy storage device power limit, atorque capacity of an electrical torque provider, a power capacity of anelectrical torque provider, and/or a detected operator braking behavior.Yet another embodiment includes determining the state of health of theelectrical energy storage device in response to a throughput event ofthe electrical energy storage device, a SOC event of the electricalenergy storage device (e.g. the SOC reaching a high or low SOC thresholdvalue), a regeneration cycle event of the electrical energy storagedevice, and/or an age of the electrical energy storage device.

An exemplary method includes determining the power division and theadjusting the power division by operating a cost comparison algorithmbetween achieving the machine power demand with the internal combustionengine and the electrical energy storage device(s).

Yet another exemplary set of embodiments is a method, includingoperating a hybrid power train including an internal combustion engineand one or more electrical torque providers. The method further includesdetermining a machine power demand and, in response to the machine powerdemand, determining a power division description. The method furtherincludes, in response to the power division description, operating theinternal combustion engine and the at least one electrical torqueprovider, where operating the internal combustion engine includesstarting the internal combustion engine in response to determining abattery SOC is about to fall below a limit.

In certain embodiments, the method includes performing engine shutdownand engine startup operations with at least one time hysteresis value.An exemplary method includes determining an engine shutdown timehysteresis value in response to a turbocharger temperature. Furtherexemplary embodiments include determining a turbocharger temperaturevalue, and preventing the engine shutdown operation in response to theturbocharger temperature value exceeding a threshold. In certainembodiments, the method includes determining that an engine shutdownoperation is requested and/or imminent, and the method further includesperforming an engine-based turbocharger cooldown operation in responseto the requested or imminent engine shutdown operation.

Certain exemplary embodiments include operating the internal combustionengine by starting the internal combustion engine in response todetermining that a power demand is about to exceed an electrical limit,determining that a battery throughput limit is about to be exceeded,and/or determining that a power demand rate of increase exceeds a limit.In certain embodiments, the method includes operating the internalcombustion engine by starting the internal combustion engine in responseto determining that a battery SOC is below a threshold and/ordetermining that a power demand is above a threshold. An exemplarymethod further includes determining an engine start capability index ofan electrical torque provider, and operating the internal combustionengine by starting the internal combustion engine in response to theengine start capability index being below a first threshold. A furtherexemplary embodiment includes operating the internal combustion engineby starting the internal combustion engine in response to determiningthat the engine start capability index is about to fall below a secondthreshold.

In certain embodiments, the method includes allowing an internalcombustion engine shutdown in response to the hybrid power trainoperating in a series mode. An exemplary method includes preventing aninternal combustion engine shutdown in response to the internalcombustion engine operating in a thermal management mode and/or awarm-up mode.

Yet another exemplary set of embodiments is a system, including a hybridpower train including an engine, a first electrical torque provider, anda second electrical torque provider, a load mechanically coupled to thehybrid power train. The hybrid power train further includes a clutchcoupled to the engine and the second electrical torque provider on afirst side, and coupled to the first electrical torque provider and theload on a second side. The system further includes an electrical energystorage device electrically coupled to the first electrical torqueprovider and the second electrical torque provider, and a controllerstructured to functionally execute operations to control the hybridpower train. The controller implements a time-based hysteresis on clutchengage-disengage.

In certain embodiments, the controller further smooths torque commandsfor the engine and the second electrical torque provider in response todetermining that a clutch engage-disengage event is one of occurring orimminent. An exemplary operation to smooth the torque commands includesapplying a rate limiter and/or a low-pass filter to the engine and/orelectrical torque provider torque commands. In certain embodiments, thecontroller performs the smoothing with a time constant that is fastrelative to a highly transient operator torque request.

In certain embodiments, the controller provides a zero torque command tothe second electrical torque provider in response to one of a clutchengaging event and/or a clutch disengaging event.

In certain embodiments, the system includes a first shaft coupling theclutch to the engine and the second electrical torque provider, and asecond shaft coupling the clutch to the first electrical torque providerand the load. The controller is further structured to close the clutchin response to determining whether a speed of the first shaft is withina predetermined speed threshold value of a speed of the second shaft. Anexemplary system further includes the controller structured to operate aclosed loop controller on a position of the clutch, where a clutchposition error value is determined in response to a difference betweenthe speed of the first shaft and the speed of the second shaft. Theclutch responding to the closed loop controller is, in one embodiment, anon-binary clutch having multiple engagement values between fully openand fully closed. In certain embodiments, the closed loop controllerincludes an integral error term.

Yet another exemplary set of embodiments is a method, includingoperating a hybrid power train including an internal combustion engine,one or more electrical torque providers, and an electrical energystorage device electrically coupled to the electrical torqueprovider(s). The method further includes determining a machine powerdemand, and in response to the machine power demand, determining a powerdivision description. In certain embodiments, the method furtherincludes interpreting a state of health for the electrical energystorage device, and adjusting the power division description in responseto the state of health for the electrical energy storage device.

In certain embodiments, the method further includes determining a stateof charge target for the electrical energy storage device in response tothe state of health for the electrical energy storage device, andfurther adjusting the power division description in response to thestate of charge target for the electrical energy storage device. Anexemplary method further includes determining the state of charge targetin response to a charging energy efficiency for the electrical energystorage device. A still further exemplary method includes determiningthe state of charge target in response to a charge-discharge energycycle efficiency for the electrical energy storage device.

In certain embodiments, the method includes determining a discharge ratelimit for the electrical energy storage device, and further adjustingthe power division description in response to the discharge rate limit.An exemplary method further includes determining the discharge ratelimit in response to a state of health of the electrical energy storagedevice, a power bus deliverability value, a motor limit for andelectrical torque provider, and/or an accessory load value. Anotherexemplary method includes determining the discharge rate limit inresponse to a power electronics throughput limit, where the powerelectronics is positioned between the electrical energy storage deviceand an electrical torque provider.

An exemplary method further includes determining a charge rate limit forthe electrical energy storage device, and further adjusting the powerdivision description in response to the charge rate limit. A stillfurther exemplary method includes determining the charge rate limit inresponse to a state of health of the electrical energy storage device, apower bus deliverability value, a motor limit for one of the electricaltorque providers, and/or an accessory load value. In certainembodiments, the method further includes determining the discharge ratelimit in response to a power electronics throughput limit, where thepower electronics is positioned between the electrical energy storagedevice and an electrical torque provider.

Yet another exemplary set of embodiments is a method, includingoperating a hybrid power train including an internal combustion engineand one or more electrical torque providers, determining a machine powerdemand, determining an audible noise limit value for the internalcombustion engine, and determining a power division description inresponse to the machine power demand and the audible noise limit value.The method further includes operating the internal combustion engine andthe electrical torque provider(s) in response to the power divisiondescription. An exemplary method further includes interpreting a noiseinput signal, and determining the audible noise limit value in responseto the noise input signal. The noise input signal may be provided by auser input.

In certain embodiments, the method includes interpreting the noise inputsignal as a response to a vehicle being in a reverse gear. In certainembodiments, the audible noise limit value is a maximum noise leveland/or a minimum noise level. An exemplary method includes determiningthe power division in response to the audible noise limit by limiting arate of change of engine power output. In certain embodiments, themethod includes determining the audible noise rate limit value for theinternal combustion engine, and adjusting the power division descriptionin response to the audible noise rate limit value.

Yet another exemplary set of embodiments is a method, including definingan application operating cycle, and defining a number of behaviormatrices for a hybrid power train that powers the application. Eachbehavior matrix corresponds to operations of the hybrid power trainoperating in a parallel configuration, where the operations of the powertrain include operations of the power providing components that form aportion of the hybrid power train. The power providing componentsinclude an internal combustion engine and at least one electrical torqueprovider. The method further includes determining a number of behaviorsequences, where each behavior sequence corresponds to one of thebehavior matrices and includes a sequential set of values created fromthe corresponding behavior matrix applied sequentially to theapplication operating cycle. The method further includes confirming afeasibility of each of the behavior sequences, and determining a fitnessvalue corresponding to each of the feasible behavior sequences. Themethod further includes determining whether a convergence valueindicates that a successful convergence has occurred in response to thefitness value corresponding to each of the feasible behavior sequences.

Where the successful convergence has not occurred, the method includesdetermining a number of child behavior matrices in response to thenumber of behavior matrices and the fitness value corresponding to eachof the feasible behavior sequences, confirming the feasibility of eachof the child behavior sequences resulting from the child behaviormatrices, and determining the fitness value corresponding to each of thefeasible child behavior sequences. The method further includesdetermining again whether the convergence value indicates that thesuccessful convergence has occurred, in response to the fitness valuecorresponding to each of the feasible child behavior sequences.

Where the successful convergence has occurred, the method includesdetermining a calibration matrix in response to the behavior matricesand the fitness values. The calibration matrix is selected from thematrices—behavior matrices or child behavior matrices—that correspond tothe successful convergence check. An exemplary operation includesselecting a behavior matrix having the best fitness function. The methodfurther includes providing the calibration matrix to a hybrid powertrain controller, and operating a hybrid power train with the hybridpower train controller.

An exemplary method further includes confirming the feasibility of eachbehavior sequence and child behavior sequence by determining whether anelectrical limit is exceeded in the corresponding behavior sequence.

An exemplary method includes determining a number of child behaviormatrices by selecting a number of parent behavior matrices from thebehavior matrices in response to the corresponding fitness functions. Afurther exemplary method includes selecting parent behavior matrices byselecting the most fit behavior matrices, and/or selecting behaviormatrices having a survival probability related to the correspondingfitness function. In certain further embodiments, the method includescrossing over behavior parameters between two or more parent behaviormatrices to determine a child behavior matrix. In certain furtherembodiments, the method includes applying a random change to a parameterof the child behavior matrix.

In still further embodiments, the method includes each of the behaviormatrices and each of the child behavior matrices having a number ofhybrid power train operating conditions, and a behavior vectorcorresponding to each of the hybrid power train operating conditions,wherein each behavior vector includes a power division description forthe power providing devices. The power division description includes apower contribution for an internal combustion engine and a powercontribution for an electrical system, or a power contribution for theinternal combustion engine and a power contribution for each of theelectrical torque providers. In certain embodiments, the number ofhybrid power train operating conditions include a machine shaft speedand a machine power demand.

In certain embodiments, the power division description includes a totalelectrical contribution and an internal combustion engine contribution.In certain further embodiments, the power division description includesan internal combustion engine contribution, a power contribution of afirst electrical torque provider, and a power contribution of a secondelectrical torque provider. In certain embodiments, each contributionincludes a discrete number of possible states, and each behavior matrixincludes the discrete number of possible states corresponding to thecontribution. For example, the internal combustion engine contributionmay include 1,024 states for horsepower from −600 hp to +475 hp (forexample in an engine having a compression brake capable of 600 hp ofbraking power and 475 hp of propulsion power), where the 1,024 statesmay be evenly divided or divided by any other scheme understood in theart.

In certain further embodiments, the discrete number of possible statescorresponding may be varied as a characteristic changeable between abehavior matrix and a child behavior matrix. An alternative oradditional embodiment includes allowing the discrete number of possiblestates of the internal combustion engine contribution to vary as acharacteristic changeable between a behavior matrix and a child behaviormatrix.

In certain embodiments, the method includes determining whether theconvergence value indicates that the successful convergence has occurredby determining whether an incremental improvement in a characteristicfitness value is lower than a convergence threshold value. In certainembodiments, the characteristic fitness function includes a best fitnessvalue. In certain further embodiments, the method includes performing asensitivity check on a behavior matrix corresponding to the best fitnessvalue. An exemplary operation to perform a sensitivity check includesdetermining whether an incremental improvement in the characteristicfitness value exceeds an acute convergence threshold value.

In certain embodiments, the application operating cycle comprises adriving route. Additional or alternative embodiments include theapplication operating cycle including a number of discrete drivingroutes having a similar duty cycle characteristic. In certainembodiments, the method includes determining a number of calibrationmatrices, each calibration matrix corresponding to one of a number ofapplication operating cycles, where each of the application operatingcycles corresponds to a distinct duty cycle characteristic. In certainfurther embodiments, the method includes determining a real-time dutycycle characteristic of the hybrid power train, and selecting one of theplurality of calibration matrices in response to the real-time dutycycle characteristic and the distinct duty cycle characteristicscorresponding to the application operating cycles during the operationof the hybrid power train. In certain embodiments, the method includesselecting one of the calibration matrices, and/or interpolating betweentwo of the calibration matrices in response to the real-time duty cyclecharacteristic and the distinct duty cycle characteristics correspondingto the application operating cycles.

In certain embodiments, the parallel configuration constrains theengine, the first electrical torque provider, and the second electricaltorque provider to operate at one of a uniform speed or at a fixed ratioof speeds. An exemplary fitness value includes a fuel economy costand/or an emissions cost. An exemplary method includes confirming thefeasibility of each behavior sequence and child behavior sequence bydetermining whether an emissions limit is exceeded in the correspondingbehavior sequence. In certain additional or alternative embodiments, themethod includes confirming the feasibility of each behavior sequence andchild behavior sequence by determining whether an aftertreatmentregeneration capability is provided in the corresponding behaviorsequence.

An exemplary fitness value further includes a secondary cost ofemissions. An exemplary secondary cost of emissions includes a servicelife cost of an aftertreatment device, an operating cost of theaftertreatment device, and/or an aftertreatment device regeneration costof the aftertreatment device.

An exemplary method includes downloading run-time data of the hybridpower train to an external computer, selecting at least a portion of therun-time data as an application operating cycle, and generating secondcalibration matrix in response to the run-time data. The externalcomputer includes a computer on-board a vehicle having the hybrid powertrain, and/or a computer external the vehicle having the hybrid powertrain. In certain embodiments, the method includes utilizing theoriginal calibration matrix as a parent behavior matrix. An additionalor alternative embodiment includes limiting an amount of change betweenthe calibration matrix and the second calibration matrix. In certainembodiments, the run-time data is compressed and stored on a controllerof the hybrid power train until the downloading.

Yet another exemplary set of embodiments is a system, including a hybridpower train having an internal combustion engine and an electricalsystem, the electrical system including a first electrical torqueprovider, a second electrical torque provider, and an electrical energystorage device electrically coupled to the first electrical torqueprovider and the second electrical torque provider. The system furtherincludes a controller structured to perform certain operations forcontrolling a hybrid power train. The controller determines a powersurplus value of the electrical system, determines a machine powerdemand change value, and operating an optimum cost controller todetermine a power division for the engine, first electrical torqueprovider, and second electrical torque provider in response to the powersurplus value of the electrical system being greater than or equal tothe machine power demand change value. An exemplary controller furtheroperates a rule-based controller to determine the power division for theengine, first electrical torque provider, and second electrical torqueprovider in response to the power surplus value of the electrical systembeing less than the machine power demand change value.

An exemplary system further includes the controller determining thepower surplus value of the first electrical torque provider in responseto the electrical system having power delivery availability to meet themachine power demand change value. In certain embodiments, thecontroller includes operating the rule-based controller in response tothe machine power demand change value exceeding a threshold.

In certain embodiments, the controller determines the power surplusvalue in response to a torque rating of the first electrical torqueprovider, a torque rating of the second electrical torque provider, anaccessory load, a throughput rating of the electrical energy storagedevice, an SOC of the electrical energy storage device, a throughputrating of a first power electronics interposed between the electricalenergy storage device and the first electrical torque provider, and/or athroughput rating of a second power electronics interposed between theelectrical energy storage device and the second electrical torqueprovider.

In certain embodiments, the controller further operates the optimum costcontroller by incrementally changing a power provided by the engine in afirst execution cycle, and determining whether the incrementally changedpower improved a power cost value. In certain further embodiments, thecontroller further operates the optimum cost controller as a closed loopcontroller having an error value determined in response to a slope ofthe power cost value with time. An exemplary optimum cost controllerincludes a proportional-integral controller. An exemplary controllerfurther applies a random noise value to the incrementally changing powerprovided by the engine. The random noise value, in certain embodiments,includes an amplitude selected in response to an expected local minimadepth property of a response surface of the hybrid power train. Incertain embodiments, the controller increases an amplitude of theincremental change in response to an increasing rate of change of thepower cost value. In certain embodiments, the system further includesthe controller commanding the first electrical torque provider to meetthe machine power demand change value.

In certain embodiments, the controller operates the rule-basedcontroller by responding to increasing power demand by, in order anduntil the power demand is achieved, increasing power of the firstelectrical torque provider, increasing power of the second electricaltorque provider, and increasing power of the engine. In certainembodiments, the controller operates the rule-based controller byresponding to decreasing power demand by, in order and until the powerdemand is achieved, decreasing power of the first electrical torqueprovider, decreasing power of the second electrical torque provider, anddecreasing power of the engine. An exemplary controller further limitsthe first electrical torque provider and the second electrical torqueprovider to a minimum zero torque until the engine reaches a minimumtorque value during a decreasing power demand.

An exemplary system further includes a clutch positioned with the firstelectrical torque provider and a load on a first side and with theinternal combustion engine and the second electrical torque provider ona second side. The clutch in a closed position provides the hybrid powertrain in a parallel configuration, and the clutch in an open positionprovides the hybrid power train in a series configuration. An exemplarysystem further includes, in response to determining the clutch is openand the power surplus value is less than the machine power demand changevalue, the controller commanding the clutch to close. Another exemplarysystem includes, in response to determining the clutch is open and thepower surplus value is less than the machine power demand change value,and further in response to determining the clutch is disallowed fromclosing, the controller commanding the first electrical torque providerto one of a maximum or minimum torque position.

A number of non-limiting exemplary embodiments and non-limiting forms ofsuch exemplary embodiments will now be described. It shall beappreciated that the embodiments and forms described below may becombined in certain instances and may be exclusive of one another inother instances. Likewise, it shall be appreciated that the embodimentsand forms described below may or may not be combined with other aspectsand features disclosed elsewhere herein.

A first exemplary embodiment is a method, including determining amachine shaft torque demand and a machine shaft speed, in response tothe machine shaft torque demand and the machine shaft speed, determininga machine power demand, determining a power division description betweenan internal combustion engine, a first electrical torque provider, and asecond electrical torque provider, determining a hybrid power trainconfiguration as one of series and parallel, determining a baselinepower division description in response to a vehicle speed and themachine power demand, determining a state-of-charge (SOC) deviation foran electrical energy storage device electrically coupled to the firstelectrical torque provider and the second electrical torque provider,and adjusting the baseline power division description in response to theSOC deviation and the hybrid power train configuration.

In some forms according to the first exemplary embodiment thedetermining the hybrid power train configuration as one of series andparallel comprises determining a clutch position including one ofengaged and disengaged, the clutch interposed between the firstelectrical torque provider on a first side and the internal combustionengine and the second electrical torque provider on a second side.

In some forms according to the first exemplary embodiment thedetermining the SOC deviation for the electrical energy storage devicecomprises determining a difference between a present SOC and a targetSOC.

Some forms according to the first exemplary embodiment further includeadjusting the SOC deviation in response to a parameter selected from theparameters consisting of: a present vehicle speed, a temperature of theelectrical energy storage device, a state-of-health of the electricalenergy storage device, the machine power demand, and an integrated SOCdeviation over time.

In some forms according to the first exemplary embodiment the baselinepower division description includes a total electrical contribution anda total engine contribution, the method further including, in responseto determining the hybrid power train configuration is parallel,adjusting the baseline power division description by dividing the totalelectrical contribution between the first electrical torque provider andthe second electrical torque provider in response to the machine shaftspeed.

Some forms according to the first exemplary embodiment further includedetermining a net power flux to the electrical energy storage device inresponse to the SOC deviation, and wherein the adjusting the baselinepower division description is in response to the net power flux.

In some forms according to the first exemplary embodiment the dividingthe total electrical contribution is in response to a first efficiencyof the first electrical torque provider at the machine shaft speed and asecond efficiency of the second electrical torque provider at themachine shaft speed.

Some forms according to the first exemplary embodiment further include,in response to determining the hybrid power train configuration isseries, adjusting the baseline power division description by commandingthe second electrical torque provider to achieve the machine powerdemand, commanding the first electrical torque provider to provide a netpower flux to the electrical energy storage device, and commanding theinternal combustion engine to power the first electrical torqueprovider.

In some forms according to the first exemplary embodiment determiningthe baseline power division description includes determining one of atotal electrical contribution and a total engine contribution, whereinthe total electrical contribution and the total engine contributioncombined provide the machine power demand, a power contribution for eachof the internal combustion engine, the first electrical torque provider,and the second electrical torque provider, wherein the total of thepower contributions provide the machine power demand, a total electricalcontribution, a total engine contribution, and a net power flux to theelectrical power storage device, wherein the total electricalcontribution, the total engine contribution, and the net power fluxcombine to provide the machine power demand, a power contribution foreach of the internal combustion engine, the first electrical torqueprovider, the second electrical torque provider, and a net power flux tothe electrical power storage device, wherein the total of the powercontributions and the net power flux provide the machine power demand, atotal electrical contribution, a total engine contribution, a net powerflux to the electrical power storage device, and a net power flux toaccessories, wherein the total electrical contribution, the total enginecontribution, the net power flux to the electrical energy storagedevice, and the net power flux to the accessories combine to provide themachine power demand, and a power contribution for each of the internalcombustion engine, the first electrical torque provider, the secondelectrical torque provider, a net power flux to the electrical powerstorage device, and a net power flux to accessories, wherein the totalof the power contributions, the net power flux to the electrical energystorage device, and the net power flux to the accessories provide themachine power demand.

Some forms according to the first exemplary embodiment further includereducing one of a SOC deviation and a response to the SOC deviation inresponse to an increasing vehicle speed.

Some forms according to the first exemplary embodiment further includeincreasing a response to the SOC deviation in response to a magnitude ofthe SOC deviation.

Some forms according to the first exemplary embodiment further includedetermining the SOC deviation in response to a target SOC, wherein thetarget SOC is determined in response to at least one parameter selectedfrom the parameters consisting of a vehicle speed, a vehicle mass, anelectrical energy storage device capacity, an electrical energy storagedevice throughput limit, a first electrical torque provider throughputlimit, a second electrical torque provider throughput limit, and anoperator braking behavior.

Some forms according to the first exemplary embodiment further includedetermining a state of health of the electrical energy storage device,and further adjusting the response to the SOC deviation in response tothe state of health.

Some forms according to the first exemplary embodiment further includeincreasing the response to the SOC deviation in response to the state ofhealth being reduced.

Some forms according to the first exemplary embodiment further includeadjusting a response to the SOC deviation in response to an operatingtemperature of the electrical energy storage device.

Some forms according to the first exemplary embodiment further includeoperating a closed loop controller having the SOC deviation as an errorvalue, wherein the closed loop controller includes an integral controlterm.

Some forms according to the first exemplary embodiment further includeadjusting one of the SOC deviation and a response to the SOC deviation,in response to the machine power demand.

Some forms according to the first exemplary embodiment further include,in response to the machine power demand being negative, increasing anSOC target for the electrical energy storage device, wherein the SOCdeviation is determined in response to the SOC target.

Some forms according to the first exemplary embodiment further include,in response to the machine power demand being high, reducing an SOCtarget for the electrical energy storage device, wherein the SOCdeviation is determined in response to the SOC target.

A second exemplary embodiment is a method including determining amachine power demand, determining a power division description betweenan internal combustion engine, a first electrical torque provider, and asecond electrical torque provider, determining a clutch positionincluding one of engaged and disengaged, the clutch interposed betweenthe first electrical torque provider on a first side and the internalcombustion engine and the second electrical torque provider on a secondside, determining a baseline power division description in response to avehicle speed and the machine power demand, determining astate-of-charge (SOC) deviation for an electrical energy storage deviceelectrically coupled to the first electrical torque provider and thesecond electrical torque provider, and adjusting the baseline powerdivision description in response to the SOC deviation and the hybridpower train configuration.

Some forms according to the second exemplary embodiment further includedetermining that the hybrid power train is in a parallel configurationin response to determining the clutch is engaged.

Some forms according to the second exemplary embodiment further includeincreasing a response to the SOC deviation in response to a magnitude ofthe SOC deviation.

Some forms according to the second exemplary embodiment further includedetermining the SOC deviation in response to a target SOC, wherein thetarget SOC is determined in response to at least one parameter selectedfrom the parameters consisting of a vehicle speed, a vehicle mass, anelectrical energy storage device capacity, an electrical energy storagedevice throughput limit, a first electrical torque provider throughputlimit, a second electrical torque provider throughput limit, and anoperator braking behavior.

Some forms according to the second exemplary embodiment further includedetermining a state of health of the electrical energy storage device,and further adjusting the response to the SOC deviation in response tothe state of health.

Some forms according to the second exemplary embodiment further includeincreasing the response to the SOC deviation in response to the state ofhealth being reduced.

A third exemplary embodiment is a method including determining a machineshaft torque demand and a machine shaft speed, in response to themachine shaft torque demand and the machine shaft speed, determining amachine power demand, determining a power division description betweenan internal combustion engine, a first electrical torque provider, and asecond electrical torque provider, determining a hybrid power trainconfiguration as one of series and parallel, determining a baselinepower division description in response to a vehicle speed and themachine power demand, determining a state-of-charge (SOC) deviation foran electrical energy storage device electrically coupled to the firstelectrical torque provider and the second electrical torque provider,wherein the determining the SOC deviation for the electrical energystorage device comprises determining a difference between a present SOCand a target SOC, and adjusting the baseline power division descriptionin response to the SOC deviation and the hybrid power trainconfiguration.

Some forms according to the third exemplary embodiment further includedetermining the SOC target SOC in response to at least one parameterselected from the parameters consisting of a state of health of theelectrical energy storage device, a vehicle speed, a vehicle mass, anelectrical energy storage device capacity, an electrical energy storagedevice throughput limit, a first electrical torque provider throughputlimit, a second electrical torque provider throughput limit, and anoperator braking behavior.

In some forms according to the third exemplary embodiment determiningthe baseline power division description comprises determining a totalelectrical contribution and a total engine contribution, wherein thetotal electrical contribution and the total engine contribution combinedprovide the machine power demand,

In some forms according to the third exemplary embodiment determiningthe baseline power division description comprises determining a powercontribution for each of the internal combustion engine, the firstelectrical torque provider, and the second electrical torque provider,wherein the total of the power contributions provide the machine powerdemand.

In some forms according to the third exemplary embodiment determiningthe baseline power division description comprises determining a totalelectrical contribution, a total engine contribution, and a net powerflux to the electrical power storage device, wherein the totalelectrical contribution, the total engine contribution, and the netpower flux combine to provide the machine power demand.

In some forms according to the third exemplary embodiment determiningthe baseline power division description comprises determining a powercontribution for each of the internal combustion engine, the firstelectrical torque provider, the second electrical torque provider, and anet power flux to the electrical power storage device, wherein the totalof the power contributions and the net power flux provide the machinepower demand.

In some forms according to the third exemplary embodiment determiningthe baseline power division description comprises determining a totalelectrical contribution, a total engine contribution, a net power fluxto the electrical power storage device, and a net power flux toaccessories, wherein the total electrical contribution, the total enginecontribution, the net power flux to the electrical energy storagedevice, and the net power flux to the accessories combine to provide themachine power demand.

In some forms according to the third exemplary embodiment determiningthe baseline power division description comprises determining a powercontribution for each of the internal combustion engine, the firstelectrical torque provider, the second electrical torque provider, a netpower flux to the electrical power storage device, and a net power fluxto accessories, wherein the total of the power contributions, the netpower flux to the electrical energy storage device, and the net powerflux to the accessories provide the machine power demand.

A fourth exemplary embodiment is a method including operating a hybridpower train having an internal combustion engine and at least oneelectrical torque provider, determining a machine power demand for thehybrid power train, determining a power division between the internalcombustion engine and the electrical torque provider in response to themachine power demand, determining a state-of-charge (SOC) of anelectrical energy storage device electrically coupled to the at leastone electrical torque provider, interpreting a target SOC for theelectrical energy storage device in response to a vehicle speed,determining an SOC deviation for the electrical storage device, whereinthe SOC deviation comprises a function of a difference between the SOCof the electrical energy storage device and the target SOC of theelectrical energy storage device, and adjusting the power division inresponse to the SOC deviation.

Some forms according to the fourth exemplary embodiment further includedecreasing the target SOC in response to an increasing vehicle speed.

Some forms according to the fourth exemplary embodiment further includeadjusting the target SOC in response to a temperature of the electricalenergy storage device.

Some forms according to the fourth exemplary embodiment further includedecreasing the target SOC in response to a decreasing temperature of theelectrical energy storage device.

Some forms according to the fourth exemplary embodiment further includeadjusting one of the target SOC and the SOC deviation in response to astate-of-health of the electrical storage device.

Some forms according to the fourth exemplary embodiment further includeincreasing the SOC deviation in response to a degraded state-of-healthof the electrical storage device.

In some forms according to the fourth exemplary embodiment thedetermining the power division and the adjusting the power divisioncomprise operating a cost comparison algorithm between achieving themachine power demand with the internal combustion engine and the atleast one electrical energy storage device.

Some forms according to the fourth exemplary embodiment further includeincreasing a cost of the SOC deviation in response to a decreasedstate-of-health of the electrical energy storage device.

Some forms according to the fourth exemplary embodiment further includedetermining the state-of-health of the electrical energy storage devicein response to at least one parameter selected from the parametersconsisting of: a throughput event of the electrical energy storagedevice, a SOC event of the electrical energy storage device, aregeneration cycle event of the electrical energy storage device, and anage of the electrical energy storage device.

Some forms according to the fourth exemplary embodiment further includedetermining the SOC deviation as a function of at least one parameterselected from the parameters consisting of: a vehicle mass, anelectrical energy storage device capacity, an electrical energy storagedevice power limit, a torque capacity of the at least one electricaltorque provider, a power capacity of the at least one electrical torqueprovider, and detected operator braking behavior.

Some forms according to the fourth exemplary embodiment further includeadjusting a target SOC of the electrical energy storage device inresponse to the state-of-health of the electrical energy storage device.

A fifth exemplary embodiment is a method including operating a hybridpower train having an internal combustion engine and at least oneelectrical torque provider, determining a state-of-charge (SOC) of anelectrical energy storage device electrically coupled to the at leastone electrical torque provider, interpreting a target SOC for theelectrical energy storage device in response to a vehicle speed,determining an SOC deviation for the electrical storage device, whereinthe SOC deviation comprises a function of a difference between the SOCof the electrical energy storage device and the target SOC of theelectrical energy storage device, and adjusting operations of the hybridpower train in response to the SOC deviation.

Some forms according to the fifth exemplary embodiment further includeincreasing the target SOC in response to a reduced vehicle speed.

Some forms according to the fifth exemplary embodiment further includereducing the target SOC in response to an increased vehicle speed.

Some forms according to the fifth exemplary embodiment further includedetermining a recoverable kinetic energy of the vehicle in response tothe vehicle speed, and wherein the interpreting the SOC target is inresponse to the recoverable kinetic energy.

Some forms according to the fifth exemplary embodiment further includedetermining a machine power demand for the hybrid power train,determining a power division between the internal combustion engine andthe electrical torque provider in response to the machine power demand,and wherein the adjusting operations of the hybrid power train compriseadjusting the power division between the internal combustion engine andthe electrical torque provider.

A sixth exemplary embodiment is a method including operating a hybridpower train having an internal combustion engine and at least oneelectrical torque provider, determining a machine shaft torque demandand a machine shaft speed, in response to the machine shaft torquedemand and the machine shaft speed, determining a machine power demand,in response to determining the machine shaft speed is zero and themachine shaft torque demand is greater than zero, adjusting the machinepower demand to a non-zero value, determining a power division betweenthe internal combustion engine and the electrical torque provider inresponse to the machine power demand, determining a state-of-charge(SOC) of an electrical energy storage device electrically coupled to theat least one electrical torque provider, interpreting a target SOC forthe electrical energy storage device in response to a vehicle speed,determining an SOC deviation for the electrical storage device, whereinthe SOC deviation comprises a function of a difference between the SOCof the electrical energy storage device and the target SOC of theelectrical energy storage device, and adjusting the power division inresponse to the SOC deviation.

Some forms according to the sixth exemplary embodiment further includedecreasing the target SOC in response to an increasing vehicle speed.

In some forms according to the sixth exemplary embodiment thedetermining the power division and the adjusting the power divisioncomprise operating a cost comparison algorithm between achieving themachine power demand with the internal combustion engine and the atleast one electrical energy storage device.

Some forms according to the sixth exemplary embodiment further includeincreasing a cost of the SOC deviation in response to a decreasedstate-of-health of the electrical energy storage device.

A seventh exemplary embodiment is a method including operating a hybridpower train including an internal combustion engine and at least oneelectrical torque provider, determining a machine power demand, inresponse to the machine power demand, determining a power divisiondescription, in response to the power division description, operatingthe internal combustion engine and the at least one electrical torqueprovider, and wherein operating the internal combustion engine furthercomprises starting the internal combustion engine in response todetermining a battery state-of-charge (SOC) is below a predeterminedthreshold value.

Some forms according to the seventh exemplary embodiment further includeperforming engine shutdown and engine startup operations with at leastone time based hysteresis value.

Some forms according to the seventh exemplary embodiment further includedetermining an engine shutdown time hysteresis value in response to aturbocharger temperature.

Some forms according to the seventh exemplary embodiment further includedetermining a turbocharger temperature value, and preventing the engineshutdown operation in response to the turbocharger temperature valueexceeding a threshold.

Some forms according to the seventh exemplary embodiment further includedetermining that an engine shutdown operation is one of requested andimminent, the method further including performing an engine-basedturbocharger cooldown operation in response to the requested or imminentengine shutdown operation.

In some forms according to the seventh exemplary embodiment theoperating the internal combustion engine further comprises starting theinternal combustion engine in response to one of determining that abattery state-of-charge (SOC) is below a threshold and determining thatthe machine power demand is above a threshold.

Some forms according to the seventh exemplary embodiment further includedetermining an engine start capability index of the at least oneelectrical torque provider, and wherein operating the internalcombustion engine further comprises starting the internal combustionengine in response to the engine start capability index being below afirst threshold.

In some forms according to the seventh exemplary embodiment theoperating the internal combustion engine further comprises starting theinternal combustion engine in response to determining that the enginestart capability index is about to fall below a second threshold.

Some forms according to the seventh exemplary embodiment further includeallowing an internal combustion engine shutdown in response to thehybrid power train operating in a series mode.

Some forms according to the seventh exemplary embodiment further includepreventing an internal combustion engine shutdown in response to theinternal combustion engine operating in one of a thermal management modeand a warm-up mode.

An eighth exemplary embodiment is a method including operating a hybridpower train including an internal combustion engine and at least oneelectrical torque provider, determining a machine power demand, inresponse to the machine power demand, determining a power divisiondescription, in response to the power division description, operatingthe internal combustion engine and the at least one electrical torqueprovider, and wherein operating the internal combustion engine furthercomprises starting the internal combustion engine in response todetermining a battery state-of-charge (SOC) is one of: below a firstpredetermined threshold value, and below a second predeterminedthreshold value and moving lower at a discharge rate exceeding adischarge threshold value.

In some forms according to the eighth exemplary embodiment operating theinternal combustion engine further comprises starting the internalcombustion engine in response to determining that a power demand isabout to exceed an electrical limit.

In some forms according to the eighth exemplary embodiment operating theinternal combustion engine further comprises starting the internalcombustion engine in response to determining that a battery throughputlimit is about to be exceeded.

In some forms according to the eighth exemplary embodiment operating theinternal combustion engine further comprises starting the internalcombustion engine in response to determining that a battery throughputvalue exceeds a battery throughput threshold and is moving higher at athroughput increase rate exceeding a throughput increase threshold.

In some forms according to the eighth exemplary embodiment operating theinternal combustion engine further comprises starting the internalcombustion engine in response to determining that a power demand rate ofincrease exceeds a limit.

A ninth exemplary embodiment is a method including operating a hybridpower train including an internal combustion engine and at least oneelectrical torque provider, determining a machine power demand, inresponse to the machine power demand, determining a power divisiondescription, in response to the power division description, operatingthe internal combustion engine and the at least one electrical torqueprovider, and wherein operating the internal combustion engine furthercomprises starting the internal combustion engine in response to one of:determining a battery state-of-charge (SOC) is below a predeterminedthreshold value, and determining the machine power demand exceeds anengine start threshold value and the machine power demand is increasing.

Some forms according to the ninth exemplary embodiment further includedetermining an engine start capability index of the at least oneelectrical torque provider, and wherein operating the internalcombustion engine further comprises starting the internal combustionengine in response to the engine start capability index being below astart capability threshold.

In some forms according to the ninth exemplary embodiment the operatingthe internal combustion engine further comprises starting the internalcombustion engine in response to determining that the engine startcapability index is about to fall below a second start capabilitythreshold.

Some forms according to the ninth exemplary embodiment further includeperforming engine shutdown and engine startup operations with at leastone time based hysteresis value.

Some forms according to the ninth exemplary embodiment further includedetermining an engine shutdown time hysteresis value in response to aturbocharger temperature.

A tenth exemplary embodiment is a system including a hybrid power trainincluding an engine, a first electrical torque provider, and a secondelectrical torque provider, a load mechanically coupled to the hybridpower train, the hybrid power train further including a clutch coupledto the engine and the second electrical torque provider on a first side,and coupled to the first electrical torque provider and the load on asecond side, an electrical energy storage device electrically coupled tothe first electrical torque provider and the second electrical torqueprovider, and a controller structured to perform operations to smoothtorque commands for the engine and the second electrical torque providerin response to determining that a clutch engage-disengage event is oneof occurring or imminent.

In some forms according to the tenth exemplary embodiment the controlleris further structured to implement a time-based hysteresis on clutchengage-disengage.

In some forms according to the tenth exemplary embodiment the controlleris further structured to smooth the torque commands by applying one of arate limiter and a low-pass filter.

In some forms according to the tenth exemplary embodiment the controlleris further structured to smooth torque commands for the engine and thesecond electrical torque provider, wherein the smoothing occurs with atime constant that is fast relative to a highly transient operatortorque request.

In some forms according to the tenth exemplary embodiment the controlleris further structured to smooth the torque commands by applying one of arate limiter and a low-pass filter.

In some forms according to the tenth exemplary embodiment the controlleris further structured to provide a zero torque command to the secondelectrical torque provider during a clutch engaging event.

In some forms according to the tenth exemplary embodiment the controlleris further structured to provide a zero torque command to the secondelectrical torque provider during a clutch disengaging event.

Some forms according to the tenth exemplary embodiment further include afirst shaft coupling the clutch to the engine and the second electricaltorque provider, a second shaft coupling the clutch to the firstelectrical torque provider and the load, wherein the controller isfurther structured to close the clutch in response to determining aspeed of the first shaft is within a predetermined speed threshold valueof a speed of the second shaft.

In some forms according to the tenth exemplary embodiment the controlleris further structured to operate a closed loop controller on a positionof the clutch, wherein a clutch position error value is determined inresponse to a difference between the speed of the first shaft and thespeed of the second shaft.

In some forms according to the tenth exemplary embodiment the closedloop controller includes an integral error term.

An eleventh exemplary embodiment is a method including determining thata clutch engage-disengage event is one of occurring or imminent, theclutch coupled to an engine and a second electrical torque provider on afirst side, and coupled to a first electrical torque provider and a loadon a second side, in response to the clutch engage-disengage event,smooth a torque command for the engine and for the second electricaltorque provider, and wherein the smoothing includes applying one of arate limiter and a low-pass filter.

Some forms according to the eleventh exemplary embodiment furtherinclude implementing a time-based hysteresis on clutch engage-disengage.

Some forms according to the eleventh exemplary embodiment furtherinclude performing the smoothing by applying the low-pass filter havinga time constant that is fast relative to a highly transient operatortorque request.

Some forms according to the eleventh exemplary embodiment furtherinclude applying the low-pass filter having a time constant that isfaster than 500 ms.

Some forms according to the eleventh exemplary embodiment furtherinclude providing a zero torque command to the second electrical torqueprovider during a clutch engaging event.

Some forms according to the eleventh exemplary embodiment furtherinclude providing a zero torque command to the second electrical torqueprovider during a clutch disengaging event.

Some forms according to the eleventh exemplary embodiment furtherinclude determining a speed of a first shaft coupling the clutch to theengine and the second electrical torque provider, determining a speed ofa second shaft coupling the clutch to the first electrical torqueprovider and the load, and closing the clutch in response to determiningthe speed of the first shaft is within a predetermined speed thresholdvalue of the speed of the second shaft.

Some forms according to the eleventh exemplary embodiment furtherinclude determining a speed of a first shaft coupling the clutch to theengine and the second electrical torque provider, determining a speed ofa second shaft coupling the clutch to the first electrical torqueprovider and the load, determining a clutch position error value inresponse to a difference between the speed of the first shaft and thespeed of the second shaft, and operating a closed loop controller on aposition of the clutch in response to the clutch position error value.

In some forms according to the eleventh exemplary embodiment the closedloop controller includes an integral error term.

A twelfth exemplary embodiment is a method including determining that aclutch engaging event is occurring, the clutch coupled to an engine anda second electrical torque provider on a first side, and coupled to afirst electrical torque provider and a load on a second side, inresponse to the clutch engaging event, smooth a torque command for theengine and for the second electrical torque provider, and determining aspeed of a first shaft coupling the clutch to the engine and the secondelectrical torque provider, determining a speed of a second shaftcoupling the clutch to the first electrical torque provider and theload, determining a clutch position error value in response to adifference between the speed of the first shaft and the speed of thesecond shaft, and operating a closed loop controller on a position ofthe clutch in response to the clutch position error value.

In some forms according to the twelfth exemplary embodiment the closedloop controller includes an integral error term.

Some forms according to the twelfth exemplary embodiment further includeproviding a zero torque command to the second electrical torque providerduring the clutch engaging event.

A thirteenth exemplary embodiment is a method including operating ahybrid power train including an internal combustion engine, at least oneelectrical torque provider, and an electrical energy storage deviceelectrically coupled to the at least one electrical torque provider,determining a machine power demand, in response to the machine powerdemand, determining a power division description, interpreting astate-of-health (SOH) for the electrical energy storage device, and inresponse to the SOH for the electrical energy storage device, adjustingthe power division description.

Some forms according to the thirteenth exemplary embodiment furtherinclude determining a state-of-charge (SOC) target for the electricalenergy storage device in response to the SOH for the electrical energystorage device, and further adjusting the power division description inresponse to the SOC target for the electrical energy storage device.

Some forms according to the thirteenth exemplary embodiment furtherinclude determining the SOC target in response to a charging energyefficiency for the electrical energy storage device.

Some forms according to the thirteenth exemplary embodiment furtherinclude determining the SOC target in response to a charge-dischargeenergy cycle efficiency for the electrical energy storage device.

Some forms according to the thirteenth exemplary embodiment furtherinclude determining a discharge rate limit for the electrical energystorage device, and further adjusting the power division description inresponse to the discharge rate limit.

Some forms according to the thirteenth exemplary embodiment furtherinclude determining the discharge rate limit in response to at least oneparameter selected from the parameters consisting of the SOH of theelectrical energy storage device, a power bus deliverability value, amotor limit for one of the electrical torque providers, and an accessoryload value.

Some forms according to the thirteenth exemplary embodiment furtherinclude determining the discharge rate limit in response to at least onepower electronics throughput limit, wherein the power electronics ispositioned between the electrical energy storage device and the at leastone electrical torque provider.

Some forms according to the thirteenth exemplary embodiment furtherinclude determining a charge rate limit for the electrical energystorage device, and further adjusting the power division description inresponse to the charge rate limit.

Some forms according to the thirteenth exemplary embodiment furtherinclude determining the charge rate limit in response to at least oneparameter selected from the parameters consisting of the SOH of theelectrical energy storage device, a power bus deliverability value, amotor limit for one of the electrical torque providers, and an accessoryload value.

Some forms according to the thirteenth exemplary embodiment furtherinclude determining the charge rate limit in response to at least onepower electronics throughput limit, wherein the power electronics ispositioned between the electrical energy storage device and the at leastone electrical torque provider.

A fourteenth exemplary embodiment is a method including operating ahybrid power train including an internal combustion engine, at least oneelectrical torque provider, and an electrical energy storage deviceelectrically coupled to the at least one electrical torque provider,determining a machine power demand, in response to the machine powerdemand, determining a power division description, interpreting astate-of-health (SOH) for the electrical energy storage device, astate-of-charge (SOC) for the electrical energy storage device, and atarget SOC for the electrical energy storage device, determining an SOCdeviation for the electrical energy device in response to the SOC forthe electrical energy storage device the target SOC for the electricalenergy storage device, and in response to the SOH for the electricalenergy storage device and the SOC deviation for the electrical energystorage device, adjusting the power division description.

Some forms according to the fourteenth exemplary embodiment furtherinclude selecting one of a plurality of SOC deviation response curves inresponse to the SOH for the electrical energy storage device.

In some forms according to the fourteenth exemplary embodiment theplurality of SOC deviation response curves provide an increasing SOCdeviation response in response to a decreasing SOH for the electricalenergy storage device.

Some forms according to the fourteenth exemplary embodiment furtherinclude interpreting the target SOC for the electrical energy storagedevice in response to the SOH for the electrical energy storage device.

Some forms according to the fourteenth exemplary embodiment furtherinclude increasing the target SOC for the electrical energy storagedevice in response to a decreasing SOH for the electrical energy storagedevice.

Some forms according to the fourteenth exemplary embodiment furtherinclude interpreting the target SOC for the electrical energy storagedevice in response to a vehicle speed value.

Some forms according to the fourteenth exemplary embodiment furtherinclude reducing the target SOC for the electrical energy storage devicein response to an increasing vehicle speed value.

A fifteenth exemplary embodiment is a method including determining amachine power demand for a hybrid power train including an internalcombustion engine, at least one electrical torque provider, and anelectrical energy storage device electrically coupled to the at leastone electrical torque provider, interpreting a state-of-health (SOH) forthe electrical energy storage device, and providing a power divisiondescription in response to the SOH for the electrical energy storagedevice and the machine power demand.

Some forms according to the fifteenth exemplary embodiment furtherinclude determining a state-of-charge (SOC) target for the electricalenergy storage device in response to the SOH for the electrical energystorage device, and adjusting the power division description in responseto the SOC target for the electrical energy storage device.

Some forms according to the fifteenth exemplary embodiment furtherinclude determining the SOC target in response to a charging energyefficiency for the electrical energy storage device.

Some forms according to the fifteenth exemplary embodiment furtherinclude determining the SOC target in response to a charge-dischargeenergy cycle efficiency for the electrical energy storage device.

Some forms according to the fifteenth exemplary embodiment furtherinclude determining a discharge rate limit for the electrical energystorage device, and adjusting the power division description in responseto the discharge rate limit.

Some forms according to the fifteenth exemplary embodiment furtherinclude determining the discharge rate limit in response to at least oneparameter selected from the parameters consisting of the SOH of theelectrical energy storage device, a power bus deliverability value, amotor limit for one of the electrical torque providers, and an accessoryload value.

Some forms according to the fifteenth exemplary embodiment furtherinclude determining the discharge rate limit in response to at least onepower electronics throughput limit, wherein the power electronics ispositioned between the electrical energy storage device and the at leastone electrical torque provider.

Some forms according to the fifteenth exemplary embodiment furtherinclude determining a charge rate limit for the electrical energystorage device, and further adjusting the power division description inresponse to the charge rate limit.

Some forms according to the fifteenth exemplary embodiment furtherinclude determining the charge rate limit in response to at least oneparameter selected from the parameters consisting of the SOH of theelectrical energy storage device, a power bus deliverability value, amotor limit for one of the electrical torque providers, and an accessoryload value.

Some forms according to the fifteenth exemplary embodiment furtherinclude determining the charge rate limit in response to at least onepower electronics throughput limit, wherein the power electronics ispositioned between the electrical energy storage device and the at leastone electrical torque provider.

A sixteenth exemplary embodiment is a method including operating ahybrid power train including an internal combustion engine and at leastone electrical torque provider, determining a machine power demand,determining an audible noise limit value for the internal combustionengine, in response to the machine power demand and the audible noiselimit value, determining a power division description, and in responseto the power division description, operating the internal combustionengine and the at least one electrical torque provider.

Some forms according to the sixteenth exemplary embodiment furtherinclude interpreting a noise input signal, and wherein determining theaudible noise limit value is in response to the noise input signal.

In some forms according to the sixteenth exemplary embodiment the noiseinput signal is provided by a user input.

In some forms according to the sixteenth exemplary embodiment the noiseinput signal is in response to a vehicle being in a reverse gear.

In some forms according to the sixteenth exemplary embodiment theaudible noise limit value comprises one of a maximum noise level and aminimum noise level.

In some forms according to the sixteenth exemplary embodimentdetermining the power division in response to the audible noise limitcomprises limiting a rate of change of engine power output.

Some forms according to the sixteenth exemplary embodiment furtherinclude determining an audible noise rate limit value for the internalcombustion engine, and adjusting the power division description inresponse to the audible noise rate limit value.

A seventeenth exemplary embodiment is a method including defining anapplication operating cycle, defining a plurality of behavior matricesfor a hybrid power train structured to power the application, whereineach behavior matrix corresponds to operations of the hybrid power trainoperating in a parallel configuration, the operations includingoperations of power providing components including a portion of thehybrid power train, wherein the power providing components comprise aninternal combustion engine and at least one electrical torque provider,determining a plurality of behavior sequences, each behavior sequencecorresponding to one of the behavior matrices and including a sequentialset of values including the corresponding behavior matrix appliedsequentially to the application operating cycle, confirming afeasibility of each of the behavior sequences, determining a fitnessvalue corresponding to each of the feasible behavior sequences, inresponse to the fitness value corresponding to each of the feasiblebehavior sequences, determining whether a convergence value indicatesthat a successful convergence has occurred, and in response todetermining that a successful convergence has occurred, determining acalibration matrix in response to the behavior matrices and the fitnessvalues, and providing the calibration matrix to a hybrid power traincontroller.

Some forms according to the seventeenth exemplary embodiment furtherinclude operating a hybrid power train with the hybrid power traincontroller.

Some forms according to the seventeenth exemplary embodiment furtherinclude, in response to determining that the successful convergence hasnot occurred, determining a plurality of child behavior matrices inresponse to the plurality of behavior matrices and the fitness valuecorresponding to each of the feasible behavior sequences, confirming thefeasibility of each of the child behavior sequences resulting from thechild behavior matrices, determining the fitness value corresponding toeach of the feasible child behavior sequences, and in response to thefitness value corresponding to each of the feasible child behaviorsequences further determining whether the convergence value indicatesthat the successful convergence has occurred.

In some forms according to the seventeenth exemplary embodiment theconfirming the feasibility of each behavior sequence and child behaviorsequence comprises determining whether an electrical limit is exceededin the corresponding behavior sequence.

In some forms according to the seventeenth exemplary embodiment thedetermining a plurality of child behavior matrices includes selecting aplurality of parent behavior matrices from the behavior matrices inresponse to the corresponding fitness functions.

Some forms according to the seventeenth exemplary embodiment furtherinclude selecting parent behavior matrices according to an operationselected from the operations consisting of: selecting the most fitbehavior matrices, and selecting behavior matrices having a survivalprobability related to the corresponding fitness function.

Some forms according to the seventeenth exemplary embodiment furtherinclude crossing over behavior parameters between two parent behaviormatrices to determine a child behavior matrix.

Some forms according to the seventeenth exemplary embodiment furtherinclude applying a random change to a parameter of the child behaviormatrix.

In some forms according to the seventeenth exemplary embodiment each ofthe behavior matrices and each of the child behavior matrices comprise:a plurality of hybrid power train operating conditions and a behaviorvector corresponding to each of the hybrid power train operatingconditions, wherein each behavior vector comprises a power divisiondescription for the power providing devices.

In some forms according to the seventeenth exemplary embodiment theplurality of hybrid power train operating conditions include a machineshaft speed and a machine power demand.

In some forms according to the seventeenth exemplary embodiment thepower division description comprises a total electrical contribution andan internal combustion engine contribution.

In some forms according to the seventeenth exemplary embodiment thepower division description comprises an internal combustion enginecontribution, a power contribution of a first electrical torqueprovider, and a power contribution of a second electrical torqueprovider.

In some forms according to the seventeenth exemplary embodiment eachcontribution includes a discrete number of possible states, and whereineach behavior matrix includes the discrete number of possible statescorresponding to the contribution.

Some forms according to the seventeenth exemplary embodiment furtherinclude allowing the discrete number of possible states corresponding toa contribution to vary.

Some forms according to the seventeenth exemplary embodiment furtherinclude allowing the discrete number of possible states of the internalcombustion engine contribution to vary.

Some forms according to the seventeenth exemplary embodiment furtherinclude determining whether the convergence value indicates that thesuccessful convergence has occurred by determining whether anincremental improvement in a characteristic fitness value is lower thana convergence threshold value.

In some forms according to the seventeenth exemplary embodiment thecharacteristic fitness value includes a best fitness value.

Some forms according to the seventeenth exemplary embodiment furtherinclude performing a sensitivity check on a behavior matrixcorresponding to the best fitness value.

Some forms according to the seventeenth exemplary embodiment furtherinclude performing the sensitivity check in response to the incrementalimprovement in the characteristic fitness value exceeding an acuteconvergence threshold value.

An eighteenth exemplary embodiment is a method including defining avehicle application operating cycle, defining a plurality of behaviormatrices for a hybrid power train structured to power the vehicle,wherein each behavior matrix corresponds to operations of the hybridpower train operating in a parallel configuration, the operationsincluding operations of power providing components including a portionof the hybrid power train, wherein the power providing componentscomprise an internal combustion engine and at least one electricaltorque provider, determining a plurality of behavior sequences, eachbehavior sequence corresponding to one of the behavior matrices andincluding a sequential set of values including the correspondingbehavior matrix applied sequentially to the vehicle applicationoperating cycle, confirming a feasibility of each of the behaviorsequences, determining a fitness value corresponding to each of thefeasible behavior sequences, in response to the fitness valuecorresponding to each of the feasible behavior sequences, determiningwhether a convergence value indicates that a successful convergence hasoccurred, and in response to determining that a successful convergencehas occurred, determining a calibration matrix in response to thebehavior matrices and the fitness values, and providing the calibrationmatrix to a hybrid power train controller.

In some forms according to the eighteenth exemplary embodiment thevehicle application operating cycle comprises a driving route.

Some forms according to the eighteenth exemplary embodiment furtherinclude determining a plurality of calibration matrices, eachcalibration matrix corresponding to one of a plurality of drivingroutes, wherein each of the driving routes corresponds to a distinctduty cycle characteristic.

Some forms according to the eighteenth exemplary embodiment furtherinclude, in response to the operating the hybrid power train,determining a real-time duty cycle characteristic of the hybrid powertrain, and selecting one of the plurality of calibration matrices inresponse to the real-time duty cycle characteristic and the distinctduty cycle characteristic corresponding to the driving routes.

Some forms according to the eighteenth exemplary embodiment furtherinclude interpolating between two of the calibration matrices inresponse to the real-time duty cycle characteristic and the distinctduty cycle characteristic corresponding to the driving routes.

In some forms according to the eighteenth exemplary embodiment thevehicle application operating cycle includes a plurality of discretedriving routes having a similar duty cycle characteristic.

Some forms according to the eighteenth exemplary embodiment furtherinclude downloading run-time data of the hybrid power train to anexternal computer, selecting at least a portion of the run-time data asa vehicle application operating cycle, and generating second calibrationmatrix in response to the run-time data.

In some forms according to the eighteenth exemplary embodiment theexternal computer comprises one of a computer on-board a vehicle havingthe hybrid power train and a computer external to the vehicle having thehybrid power train.

In some forms according to the eighteenth exemplary embodiment theoriginal calibration matrix is utilized as a parent behavior matrix.

Some forms according to the eighteenth exemplary embodiment furtherinclude limiting an amount of change between the calibration matrix andthe second calibration matrix.

In some forms according to the eighteenth exemplary embodiment therun-time data is compressed and stored on a controller of the hybridpower train until the downloading.

An nineteenth exemplary embodiment is a method including defining anapplication operating cycle, defining a plurality of behavior matricesfor a hybrid power train structured to power the application, whereineach behavior matrix corresponds to operations of the hybrid power trainoperating in a parallel configuration, the operations includingoperations of power providing components including a portion of thehybrid power train, wherein the power providing components comprise aninternal combustion engine and at least one electrical torque provider,determining a plurality of behavior sequences, each behavior sequencecorresponding to one of the behavior matrices and including a sequentialset of values including the corresponding behavior matrix appliedsequentially to the application operating cycle, determining a fitnessvalue corresponding to each of the behavior sequences, in response tothe fitness value corresponding to each of the behavior sequences,determining whether a convergence value indicates that a successfulconvergence has occurred, and in response to determining that asuccessful convergence has occurred, determining a calibration matrix inresponse to the behavior matrices and the fitness values, and providingthe calibration matrix to a hybrid power train controller.

Some forms according to the nineteenth exemplary embodiment furtherinclude, in response to determining that the successful convergence hasnot occurred, determining a plurality of child behavior matrices inresponse to the plurality of behavior matrices and the fitness valuecorresponding to each of the behavior sequences, determining the fitnessvalue corresponding to each of the child behavior sequences, and inresponse to the fitness value corresponding to each of the childbehavior sequences further determining whether the convergence valueindicates that the successful convergence has occurred.

Some forms according to the nineteenth exemplary embodiment furtherinclude confirming a feasibility of each of the behavior sequences,wherein the determining the fitness value comprises determining thefitness value corresponding to each of the feasible sequences.

Some forms according to the nineteenth exemplary embodiment furtherinclude, in response to determining that the successful convergence hasnot occurred, determining a plurality of child behavior matrices inresponse to the plurality of behavior matrices and the fitness valuecorresponding to each of the feasible behavior sequences, confirming thefeasibility of each of the child behavior sequences resulting from thechild behavior matrices, determining the fitness value corresponding toeach of the feasible child behavior sequences, and in response to thefitness value corresponding to each of the feasible child behaviorsequences further determining whether the convergence value indicatesthat the successful convergence has occurred.

In some forms according to the nineteenth exemplary embodiment theconfirming the feasibility of each behavior sequence and child behaviorsequence comprises determining whether an emissions limit is exceeded inthe corresponding behavior sequence.

In some forms according to the nineteenth exemplary embodiment theconfirming the feasibility of each behavior sequence and child behaviorsequence comprises determining whether an aftertreatment regenerationcapability is provided in the corresponding behavior sequence.

In some forms according to the nineteenth exemplary embodiment theparallel configuration constrains the engine, the first electricaltorque provider, and the second electrical torque provider to operate atone of a uniform speed or at a fixed ratio of speeds.

In some forms according to the nineteenth exemplary embodiment thefitness value comprises a fuel economy cost.

In some forms according to the nineteenth exemplary embodiment thefitness value comprises an emissions cost.

In some forms according to the nineteenth exemplary embodiment thefitness value comprises a secondary cost of emissions.

In some forms according to the nineteenth exemplary embodiment thesecondary cost of emissions comprises at least one secondary costselected from the secondary costs consisting of: a service life cost ofan aftertreatment device, an operating cost of the aftertreatmentdevice, and an aftertreatment device regeneration cost of theaftertreatment device.

A twentieth exemplary embodiment is a method including a hybrid powertrain including an internal combustion engine and an electrical system,the electrical system including a first electrical torque provider, asecond electrical torque provider, and an electrical energy storagedevice electrically coupled to the first electrical torque provider andthe second electrical torque provider, a controller structured toperform operations including: determining a power surplus value of theelectrical system, determining a machine power demand change value, inresponse to the power surplus value of the electrical system beinggreater than or equal to the machine power demand change value,operating an optimum cost controller to determine a power division forthe engine, first electrical torque provider, and second electricaltorque provider, and in response to the power surplus value of theelectrical system being less than the machine power demand change value,operating a rule-based controller to determine the power division forthe engine, first electrical torque provider, and second electricaltorque provider.

In some forms according to the twentieth exemplary embodiment thecontroller is further structured to determine the power surplus value ofthe first electrical torque provider in response to the electricalsystem having power delivery availability to meet the machine powerdemand change value.

In some forms according to the twentieth exemplary embodiment further inresponse to the machine power demand change value exceeding a threshold,the controller is further structured to operate the rule-basedcontroller.

In some forms according to the twentieth exemplary embodiment thecontroller is further structured to determine the power surplus value inresponse to at least one parameter selected from the parametersconsisting of: a torque rating of the first electrical torque provider,a torque rating of the second electrical torque provider, an accessoryload, a throughput rating of the electrical energy storage device, astate-of-charge (SOC) of the electrical energy storage device, athroughput rating of a first power electronics interposed between theelectrical energy storage device and the first electrical torqueprovider, and a throughput rating of a second power electronicsinterposed between the electrical energy storage device and the secondelectrical torque provider.

In some forms according to the twentieth exemplary embodiment thecontroller is further structured to operate the optimum cost controllerby incrementally changing a power provided by the engine in a firstexecution cycle, and determining whether the incrementally changed powerimproved a power cost value.

In some forms according to the twentieth exemplary embodiment thecontroller is further structured to operate the optimum cost controlleras a closed loop controller having an error value determined in responseto a slope of the power cost value with time.

In some forms according to the twentieth exemplary embodiment theoptimum cost controller is a proportional-integral controller.

In some forms according to the twentieth exemplary embodiment thecontroller is further structured to apply a random noise value to theincrementally changing power provided by the engine.

In some forms according to the twentieth exemplary embodiment the randomnoise value comprises an amplitude selected in response to an expectedlocal minima depth property of a response surface of the hybrid powertrain.

In some forms according to the twentieth exemplary embodiment thecontroller is further structured to increase an amplitude of theincremental change in response to an increasing rate of change of thepower cost value.

In some forms according to the twentieth exemplary embodiment thecontroller is further structured to operate the rule-based controller torespond to increasing power demand by, in order and until the powerdemand is achieved, increasing power output of the first electricaltorque provider, increasing power output of the second electrical torqueprovider, and increasing power output of the engine.

In some forms according to the twentieth exemplary embodiment thecontroller is further structured to operate the rule-based controller toresponse to decreasing power demand by, in order and until the powerdemand is achieved, decreasing power of the first electrical torqueprovider, decreasing power of the second electrical torque provider, anddecreasing power of the engine.

Some forms according to the twentieth exemplary embodiment furtherinclude limiting the first electrical torque provider and the secondelectrical torque provider to a minimum zero torque until the enginereaches a minimum torque value.

Some forms according to the twentieth exemplary embodiment furtherinclude a clutch positioned with the first electrical torque providerand a load on a first side and with the internal combustion engine andthe second electrical torque provider on a second side, wherein theclutch in a closed position provides the hybrid power train in aparallel configuration and wherein the clutch in an open positionprovides the hybrid power train in a series configuration.

Some forms according to the twentieth exemplary embodiment furtherinclude, in response to determining the clutch is open and the powersurplus value being less than the machine power demand change value, thecontroller further structured to command the clutch to close.

Some forms according to the twentieth exemplary embodiment furtherinclude, in response to determining the clutch is open and the powersurplus value being less than the machine power demand change value, andfurther in response to determining the clutch is disallowed fromclosing, the controller further structured to command the firstelectrical torque provider to one of a maximum or minimum torqueposition.

In some forms according to the twentieth exemplary embodiment thecontroller is further structured to command the first electrical torqueprovider to meet the machine power demand change value.

A twenty-first exemplary embodiment is a method including determining apower surplus value of an electrical system including a portion of ahybrid power train, determining a machine power demand change value, inresponse to the power surplus value of the electrical system beinggreater than or equal to the machine power demand change value,operating an optimum cost controller to determine a power division forthe hybrid power train including an engine, a first electrical torqueprovider, and a second electrical torque provider, and in response tothe power surplus value of the electrical system being less than themachine power demand change value, operating a rule-based controller todetermine the power division for the hybrid power train.

Some forms according to the twenty-first exemplary embodiment furtherinclude determining the power surplus value of the first electricaltorque provider in response to the electrical system having powerdelivery availability to meet the machine power demand change value.

Some forms according to the twenty-first exemplary embodiment furtherinclude operating a rule-based controller in response to the machinepower demand change value exceeding a threshold.

Some forms according to the twenty-first exemplary embodiment furtherinclude determining the power surplus value in response to a torquerating of at least one of the first electrical device and the secondelectrical device.

Some forms according to the twenty-first exemplary embodiment furtherinclude determining the power surplus value in response to an accessoryload.

Some forms according to the twenty-first exemplary embodiment furtherinclude determining the power surplus value in response to a throughputrating of an electrical energy storage device electrically coupled tothe first electrical torque provider and the second electrical torqueprovider.

Some forms according to the twenty-first exemplary embodiment furtherinclude determining the power surplus value in response to astate-of-charge (SOC) of an electrical energy storage deviceelectrically coupled to the first electrical torque provider and thesecond electrical torque provider.

Some forms according to the twenty-first exemplary embodiment furtherinclude determining the power surplus value in response to at least oneof a throughput rating of a first power electronics interposed betweenan electrical energy storage device and the first electrical torqueprovider, and a throughput rating of a second power electronicsinterposed between the electrical energy storage device and the secondelectrical torque provider, the electrical energy storage deviceelectrically coupled to the first electrical torque provider and thesecond electrical torque provider.

Some forms according to the twenty-first exemplary embodiment furtherinclude operating the optimum cost controller by incrementally changinga power provided by the engine in a first execution cycle, anddetermining whether the incrementally changed power improved a powercost value.

Some forms according to the twenty-first exemplary embodiment furtherinclude operating the optimum cost controller as a closed loopcontroller having an error value determined in response to a slope ofthe power cost value with time.

Some forms according to the twenty-first exemplary embodiment furtherinclude applying a random noise value to the incrementally changingpower provided by the engine.

Some forms according to the twenty-first exemplary embodiment furtherinclude selecting an amplitude for the random noise value in response toan expected local minima depth property of a response surface of thehybrid power train.

Some forms according to the twenty-first exemplary embodiment furtherinclude increasing an amplitude of the incremental change in response toan increasing rate of change of the power cost value.

Some forms according to the twenty-first exemplary embodiment furtherinclude operating the rule-based controller to respond to increasingpower demand by, in order and until the power demand is achieved,increasing power output of the first electrical torque provider,increasing power output of the second electrical torque provider, andincreasing power output of the engine.

Some forms according to the twenty-first exemplary embodiment furtherinclude operating the rule-based controller to response to decreasingpower demand by, in order and until the power demand is achieved,decreasing power of the first electrical torque provider, decreasingpower of the second electrical torque provider, and decreasing power ofthe engine.

Some forms according to the twenty-first exemplary embodiment furtherinclude limiting the first electrical torque provider and the secondelectrical torque provider to a minimum zero torque until the enginereaches a minimum torque value.

Some forms according to the twenty-first exemplary embodiment furtherinclude commanding a clutch in a closed position to position the hybridpower train in a parallel configuration, wherein the clutch ispositioned with the first electrical torque provider and a load on afirst side and with the internal combustion engine and the secondelectrical torque provider on a second side.

Some forms according to the twenty-first exemplary embodiment furtherinclude commanding the clutch in an open position to position the hybridpower train in a series configuration.

Some forms according to the twenty-first exemplary embodiment furtherinclude, in response to determining the clutch is open and the powersurplus value is less than the machine power demand change value,commanding the clutch to the closed position.

Some forms according to the twenty-first exemplary embodiment furtherinclude, in response to determining the clutch is open and the powersurplus value is less than the machine power demand change value, andfurther in response to determining the clutch is disallowed fromclosing, commanding the first electrical torque provider to one of amaximum or minimum torque position.

A twenty-second exemplary embodiment is a method including determining amachine shaft torque demand and a machine shaft speed, in response tothe machine shaft torque demand and the machine shaft speed, determininga machine power demand, in response to determining the machine shaftspeed is zero and the machine shaft torque demand is greater than zero,adjusting the machine power demand to a non-zero value, determining apower division description between an internal combustion engine and atleast one electrical torque provider, and operating the internalcombustion engine and the at least one electrical torque provider inresponse to the power division description.

Some forms according to the twenty-second exemplary embodiment furtherinclude determining an engine cost function including engine operatingcost as a function of engine power output, an electrical cost functionincluding electrical torque provider operating cost as a function of theelectrical torque provider power output, and where the determining thepower division description is in response to the engine cost functionand the electrical cost function.

In some forms according to the twenty-second exemplary embodiment theelectrical cost function includes an efficiency of corresponding powerelectronics, the corresponding power electronics interposed between theelectrical torque provider and an electrical energy storage device.

In some forms according to the twenty-second exemplary embodiment theelectrical cost function includes a generating operating region, andwherein the electrical cost function further includes an efficiency ofelectrical energy storage and recovery.

Some forms according to the twenty-second exemplary embodiment furtherinclude determining a second electrical cost function including a secondelectrical torque provider operating cost as a function of a secondelectrical torque provider power output, where the determining the powerdivision description is further in response to the engine cost function,the electrical cost function, and the second electrical cost function.

In some forms according to the twenty-second exemplary embodiment thesecond electrical cost function includes an efficiency of correspondingsecond power electronics, the corresponding second power electronicsinterposed between the second electrical torque provider and theelectrical energy storage device.

In some forms according to the twenty-second exemplary embodiment thesecond electrical cost function includes a generating operating region,and wherein the second electrical cost function further includes asecond efficiency of electrical energy storage and recoverycorresponding to the second electrical torque provider and the secondpower electronics.

Some forms according to the twenty-second exemplary embodiment furtherinclude in a first operating mode, disengaging a clutch between theinternal combustion engine and the first electrical torque provider, andproviding all of the machine power demand with the first electricaltorque provider, in a second operating mode, engaging the clutch betweenthe internal combustion engine and the first electrical torque providerand providing all of the machine power demand with the internalcombustion engine, in a third operating mode, engaging the clutchbetween the internal combustion engine and the first electrical torqueprovider and dividing the machine power demand between the internalcombustion engine and the first electrical torque provider, in a fourthoperating mode, engaging the clutch between the internal combustionengine and the first electrical torque provider and dividing the powerbetween the internal combustion engine and the second electrical torqueprovider, in a fifth operating mode, engaging the clutch between theinternal combustion engine and the first electrical torque provider anddividing the power between the first electrical torque provider and thesecond electrical torque provider, and in a sixth operating mode,engaging the clutch between the internal combustion engine and the firstelectrical torque provider and dividing the power between the internalcombustion engine, the first electrical torque provider, and the secondelectrical torque provider.

Some forms according to the twenty-second exemplary embodiment furtherinclude determining a cost disposition parameter, and whereindetermining each of the cost functions comprises determining each costfunction in response to the cost disposition parameter and a pluralityof corresponding cost functions.

In some forms according to the twenty-second exemplary embodiment thecost disposition parameter comprises one of a duty cycle category and adrive route parameter.

In some forms according to the twenty-second exemplary embodimentdetermining each cost function in response to the cost dispositionparameter and a plurality of corresponding cost functions comprises oneof: selecting one of the corresponding cost functions, and interpolatingbetween two proximate cost functions from the corresponding costfunctions.

Some forms according to the twenty-second exemplary embodiment furtherinclude adjusting the power division description in response to anelectrical storage device state-of-charge.

Some forms according to the twenty-second exemplary embodiment furtherinclude determining the electrical cost function including theelectrical torque provider operating cost as a function of theelectrical torque provider power output and an electrical energy storagedevice state-of-charge.

Some forms according to the twenty-second exemplary embodiment furtherinclude determining the electrical cost function including theelectrical torque provider operating cost as a function of theelectrical torque provider power output and an electrical energy storagedevice state-of-charge, and determining the second electrical costfunction including the second electrical torque provider operating costas a function of the second electrical torque provider power output andthe electrical energy storage device state-of-charge.

Some forms according to the twenty-second exemplary embodiment furtherinclude determining a vehicle speed, and determining the power divisiondescription in response to the machine power demand and the vehiclespeed.

Some forms according to the twenty-second exemplary embodiment furtherinclude determining a plurality of nominal power division descriptionsas a two-dimensional function of the vehicle speed and the machine powerdemand, where the determining the power division description furthercomprises a lookup operation utilizing the plurality of nominal powerdivision descriptions.

Some forms according to the twenty-second exemplary embodiment furtherinclude determining the power division description between the internalcombustion engine, a first electrical torque provider, and a secondelectrical torque provider.

Some forms according to the twenty-second exemplary embodiment furtherinclude, in response to determining that the second electrical torqueprovider provides the entire machine torque demand: disengaging a clutchpositioned between the internal combustion engine and the secondelectrical torque provider.

In some forms according to the twenty-second exemplary embodiment theengine cost function further includes an emissions cost.

In some forms according to the twenty-second exemplary embodiment theengine cost function further includes a second emissions cost.

In some forms according to the twenty-second exemplary embodiment theengine cost function further includes a secondary effect cost, whereinthe secondary effect is selected from the effects consisting of: anincremental life loss of an aftertreatment component and an incrementalregeneration cost of the aftertreatment component.

In some forms according to the twenty-second exemplary embodiment theemissions cost includes a discontinuity.

In some forms according to the twenty-second exemplary embodiment themachine power demand is negative.

In some forms according to the twenty-second exemplary embodiment thepower division description includes an engine braking target powervalue.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly certain exemplary embodiments have been shown and described andthat all changes and modifications that come within the spirit of theinventions are desired to be protected. It should be understood thatwhile the use of words such as preferable, preferably, preferred or morepreferred utilized in the description above indicate that the feature sodescribed may be more desirable, it nonetheless may not be necessary andembodiments lacking the same may be contemplated as within the scope ofthe invention, the scope being defined by the claims that follow. Inreading the claims, it is intended that when words such as “a,” “an,”“at least one,” or “at least one portion” are used there is no intentionto limit the claim to only one item unless specifically stated to thecontrary in the claim. When the language “at least a portion” and/or “aportion” is used the item can include a portion and/or the entire itemunless specifically stated to the contrary.

1.-73. (canceled)
 74. A system comprising: a hybrid power trainincluding an engine, a first electrical torque provider, and a secondelectrical torque provider; a load mechanically coupled to the hybridpower train; the hybrid power train further comprising a clutch coupledto the engine and the second electrical torque provider on a first side,and coupled to the first electrical torque provider and the load on asecond side; an electrical energy storage device electrically coupled tothe first electrical torque provider and the second electrical torqueprovider; and a controller structured to perform operations to smoothtorque commands for the engine and the second electrical torque providerin response to determining that a clutch engage-disengage event is oneof occurring or imminent.
 75. The system of claim 74, wherein thecontroller is further structured to implement a time-based hysteresis onclutch engage-disengage.
 76. The system of claim 74, wherein thecontroller is further structured to smooth the torque commands byapplying one of a rate limiter and a low-pass filter.
 77. The system ofclaim 74, wherein the controller is further structured to smooth torquecommands for the engine and the second electrical torque provider,wherein the smoothing occurs with a time constant that is fast relativeto a highly transient operator torque request.
 78. The system of claim77, wherein the controller is further structured to smooth the torquecommands by applying one of a rate limiter and a low-pass filter. 79.The system of claim 74, wherein the controller is further structured toprovide a zero torque command to the second electrical torque providerduring a clutch engaging event.
 80. The system of claim 79, wherein thecontroller is further structured to provide a zero torque command to thesecond electrical torque provider during a clutch disengaging event. 81.The system of claim 74, further comprising a first shaft coupling theclutch to the engine and the second electrical torque provider, a secondshaft coupling the clutch to the first electrical torque provider andthe load, wherein the controller is further structured to close theclutch in response to determining a speed of the first shaft is within apredetermined speed threshold value of a speed of the second shaft. 82.The system of claim 81, wherein the controller is further structured tooperate a closed loop controller on a position of the clutch, wherein aclutch position error value is determined in response to a differencebetween the speed of the first shaft and the speed of the second shaft.83. The system of claim 82, wherein the closed loop controller includesan integral error term.
 84. A method comprising: determining that aclutch engage-disengage event is one of occurring or imminent, theclutch coupled to an engine and a second electrical torque provider on afirst side, and coupled to a first electrical torque provider and a loadon a second side; in response to the clutch engage-disengage event,smooth a torque command for the engine and for the second electricaltorque provider; and wherein the smoothing includes applying one of arate limiter and a low-pass filter.
 85. The method of claim 84, furthercomprising implementing a time-based hysteresis on clutchengage-disengage.
 86. The method of claim 84, further comprisingperforming the smoothing by applying the low-pass filter having a timeconstant that is fast relative to a highly transient operator torquerequest.
 87. The method of claim 86, further comprising applying thelow-pass filter having a time constant that is faster than 500 ms. 88.The method of claim 84, further comprising providing a zero torquecommand to the second electrical torque provider during a clutchengaging event.
 89. The method of claim 84, further comprising providinga zero torque command to the second electrical torque provider during aclutch disengaging event.
 90. The method of claim 84, further comprisingdetermining a speed of a first shaft coupling the clutch to the engineand the second electrical torque provider, determining a speed of asecond shaft coupling the clutch to the first electrical torque providerand the load, and closing the clutch in response to determining thespeed of the first shaft is within a predetermined speed threshold valueof the speed of the second shaft.
 91. The method of claim 90, furthercomprising determining a speed of a first shaft coupling the clutch tothe engine and the second electrical torque provider, determining aspeed of a second shaft coupling the clutch to the first electricaltorque provider and the load, determining a clutch position error valuein response to a difference between the speed of the first shaft and thespeed of the second shaft, and operating a closed loop controller on aposition of the clutch in response to the clutch position error value.92. The system of claim 91, wherein the closed loop controller includesan integral error term.
 93. A method comprising: determining that aclutch engaging event is occurring, the clutch coupled to an engine anda second electrical torque provider on a first side, and coupled to afirst electrical torque provider and a load on a second side; inresponse to the clutch engaging event, smooth a torque command for theengine and for the second electrical torque provider; and determining aspeed of a first shaft coupling the clutch to the engine and the secondelectrical torque provider, determining a speed of a second shaftcoupling the clutch to the first electrical torque provider and theload, determining a clutch position error value in response to adifference between the speed of the first shaft and the speed of thesecond shaft, and operating a closed loop controller on a position ofthe clutch in response to the clutch position error value.
 94. Themethod of claim 93, wherein the closed loop controller includes anintegral error term.
 95. The method of claim 93, further comprisingproviding a zero torque command to the second electrical torque providerduring the clutch engaging event. 96.-231. (canceled)